Diamino-Pyridine, Pyrimidine, and Pyrazine Modulators of the Histamine H4 Receptor

ABSTRACT

Diamino-pyridine, pyrimidine and pyridazine compounds which may be used as H 4  receptor modulators, and in pharmaceutical compositions and methods for the treatment of disease states, disorders, and conditions mediated by H 4  receptor activity, such as allergy, asthma, autoimmune diseases, and pruritis.

FIELD OF THE INVENTION

The present invention relates to certain diamino-pyridine, pyrimidine, and pyridazine compounds, pharmaceutical compositions containing them, methods of making them, and methods of using them for the modulation of the histamine H₄ receptor and for the treatment of disease states, disorders, and conditions mediated by histamine H₄ receptor activity.

BACKGROUND OF THE INVENTION

The histamine H₄ receptor (H₄R), sometimes also referred to simply as “H4” or “H₄”, is the most recently identified receptor for histamine (for reviews, see: Fung-Leung, W--P., et al., Curr. Opin. Invest. Drugs 2004, 5 (11), 1174-1183; de Esch, I. J. P., et al., Trends Pharmacol. Sci. 2005, 26 (9), 482-469; Zhang, M. et al. Pharmacol. Ther. 2007, 113, 594-608; Thurmond, R. L. et al. Nat. Rev. Drug Disc. 2008, 7, 41-53; Zhang, M. et al. Expert Opin. Investig. Drugs 2006, 15 (11), 1443-1452). The receptor is found in the bone marrow and spleen and is expressed on eosinophils, basophils, mast cells (Liu, C., et al., Mol. Pharmacol. 2001, 59 (3), 420-428; Morse, K. L., et al., J. Pharmacol. Exp. Ther. 2001, 296 (3), 1058-1066; Hofstra, C. L., et al., J. Pharmacol. Exp. Ther. 2003, 306 (3), 1212-1221; Lippert, U., et al., J. Invest. Dermatol. 2004, 123 (1), 116-123; Voehringer, D., et al., Immunity 2004, 20 (3), 267-277), CD8⁺ T cells (Gantner, F., et al., J. Pharmacol. Exp. Ther. 2002, 303 (1), 300-307), dendritic cells, and human synovial cells from rheumatoid arthritis patients (Ikawa, Y., et al., Biol. Pharm. Bull. 2005, 28 (10), 2016-2018). The histamine H₄ receptor is also elevated in human nasal polyp tissue (Jókúti, A. et al. Cell. Biol. Int. 2007, 31, 1367-1370). However, expression in neutrophils and monocytes is less well defined (Ling, P., et al., Br. J. Pharmacol. 2004, 142 (1), 161-171; Darnaj, B. B. et al. J. Immunol. 2007, 179, 7907-7915). Receptor expression is at least in part controlled by various inflammatory stimuli (Coge, F., et al., Biochem. Biophys. Res. Commun. 2001, 284 (2), 301-309; Morse, et al., 2001), thus supporting that H₄ receptor activation influences inflammatory responses. Because of its preferential expression on immunocompetent cells, the H₄ receptor is closely related with the regulatory functions of histamine during the immune response.

A biological activity of histamine in the context of immunology and autoimmune diseases is closely related with the allergic response and its deleterious effects, such as inflammation. Events that elicit the inflammatory response include physical stimulation (including trauma), chemical stimulation, infection, and invasion by a foreign body. The inflammatory response is characterized by pain, increased temperature, redness, swelling, reduced function, or a combination of these.

Mast cell degranulation (exocytosis) releases histamine and leads to an inflammatory response that may be initially characterized by a histamine-modulated wheal and flare reaction. A wide variety of immunological stimuli (e.g., allergens or antibodies) and non-immunological (e.g., chemical) stimuli may cause the activation, recruitment, and de-granulation of mast cells. Mast cell activation initiates allergic inflammatory responses, which in turn cause the recruitment of other effector cells that further contribute to the inflammatory response. It has been shown that histamine induces chemotaxis of mouse mast cells (Hofstra, et al., 2003). Chemotaxis does not occur using mast cells derived from H₄ receptor knockout mice. Furthermore, the response is blocked by an H₄-specific antagonist, but not by H₁, H₂ or H₃ receptor antagonists (Hofstra, et al., 2003; Thurmond, R. L., et al., J. Pharmacol. Exp. Ther. 2004, 309 (1), 404-413). The in vivo migration of mast cells to histamine has also been investigated and shown to be H₄ receptor dependent (Thurmond, et al., 2004). The migration of mast cells may play a role in allergic rhinitis and allergy where increases in mast cell number are found (Kirby, J. G., et al., Am. Rev. Respir. Dis. 1987, 136 (2), 379-383; Crimi, E., et al., Am. Rev. Respir. Dis. 1991, 144 (6), 1282-1286; Amin, K., et al., Am. J. Resp. Crit. Care Med. 2000, 162 (6), 2295-2301; Gauvreau, G. M., et al., Am. J. Resp. Crit. Care Med. 2000, 161 (5), 1473-1478; Kassel, O., et al., Clin. Exp. Allergy 2001, 31 (9), 1432-1440). In addition, it is known that in response to allergens there is a redistribution of mast cells to the epithelial lining of the nasal mucosa (Fokkens, W. J., et al., Clin. Exp. Allergy 1992, 22 (7), 701-710; Slater, A., et al., J. Laryngol. Otol. 1996, 110, 929-933). These results show that the chemotactic response of mast cells to histamine is mediated by histamine H₄ receptors.

It has been shown that eosinophils can chemotax towards histamine (O'Reilly, M., et al., J. Recept. Signal Transduction 2002, 22 (1-4), 431-448; Buckland, K. F., et al., Br. J. Pharmacol. 2003, 140 (6), 1117-1127; Ling et al., 2004). Using H₄ selective ligands, it has been shown that histamine-induced chemotaxis of eosinophils is mediated through the H₄ receptor (Buckland, et al., 2003; Ling et al., 2004). Cell surface expression of adhesion molecules CD11b/CD18 (LFA-1) and CD54 (ICAM-1) on eosinophils increases after histamine treatment (Ling, et al., 2004). This increase is blocked by H₄ receptor antagonists but not by H₁, H₂, or H₃ receptor antagonists.

The H₄R also plays a role in dendritic cells and T cells. In human monocyte-derived dendritic cells, H₄R stimulation suppresses IL-12p70 production and drives histamine-mediated chemotaxis (Gutzmer, R., et al., J. Immunol. 2005, 174 (9), 5224-5232). A rote for the H₄ receptor in CD8⁺ T cells has also been reported. Gantner, et al., (2002) showed that both H₄ and H₂ receptors control histamine-induced IL-16 release from human CD8⁺ T cells. IL-16 is found in the bronchoalveolar fluid of allergen- or histamine-challenged asthmatics (Mashikian, V. M., et al., J. Allergy Clin. Immunol. 1998, 101 (6, Part 1), 736-792; Krug, N., et al., Am. J. Resp. Crit. Care Med. 2000, 182 (1), 105-111) and is considered important in CD4⁺ cell migration. The activity of the receptor in these cell types indicates an important role in adaptive immune responses such as those active in autoimmune diseases.

In vivo H₄ receptor antagonists were able to block neutrophillia in zymosan-induced peritonitis or pleurisy models (Takeshita, K., et al., J. Pharmacol. Exp. Ther. 2003, 307 (3), 1072-1078; Thurmond, et al., 2004). In addition, H₄ receptor antagonists have activity in a widely used and well-characterized model of colitis (Varga, C., et al., Eur. J. Pharmacol. 2005, 522 (1-3), 130-138). These results support the conclusion that H₄ receptor antagonists have the capacity to be anti-inflammatory in vivo.

Another physiological role of histamine is as a mediator of itch and H₁ receptor antagonists are not completely effective in the clinic. Recently, the H₄ receptor has also been implicated in histamine-induced scratching in mice (Bell, J. K., et al., Br. J. Pharmacol. 2004, 142 (2), 374-380). The effects of histamine could be blocked by H₄ antagonists. These results support the hypothesis that the H₄ receptor is involved in histamine-induced itch and that ₄ receptor antagonists will therefore have positive effects in treating pruritis. Histamine H₄ receptor antagonists have been shown to attenuate experimental pruritis (Dunford, P. J. et al. J. Allergy Clin. Immunol. 2007, 119 (1), 178-183).

Modulation of H₄ receptors controls the release of inflammatory mediators and inhibits leukocyte recruitment, thus providing the ability to prevent and/or treat H₄-mediated diseases and conditions, including the deleterious effects of allergic responses such as inflammation. Compounds according to the present invention have H₄ receptor modulating properties. Compounds according to the present invention have leukocyte recruitment inhibiting properties. Compounds according to the present invention have anti-inflammatory properties. Modulation of the histamine H₄ receptor has also been implicated in the treatment of pain (Intl. Pat. Appl. Publ. WO 2008/060786 (Abbott).

Numerous pro-inflammatory cytokines have been increasingly reported to be elevated in patients suffering of major depression (Frommberger et al., European Archives of Psychiatry & Clinical Neuroscience. 1997, 247 (4), 228-33; Sluzewska A., et al., Psychiatry Research, 1996, 64 (3), 161-7; Ortiz-Dominguez, et al., Bip. Disporder 9, 2007; O'Brien, et al., J. Affective Disorders, 2006, 90, 263-267; Anisman H. et al., Biological Psychiatry, 1999, 46 (12), 1649-55) (when compared with non-depressed subjects or, in some cases, correlated with symptom severity). These include increased acute-phase proteins (Kling et al., Biol. Psychiatry, 2007, 62, 309-313; Kim et al., Progress in Neuro-Psychopharmocology & Biological Psychiatry, 2007, 31, 1044-1053; (C-reactive protein, α-1-acid glycoprotein, α-1-antichymotrypsin and haptoglobin), increased expression of chemokines and adhesion molecules (including human macrophage chemoattractant protein-1 (MCP-1), soluble intracellular adhesion molecule-1 (sICAM-1) and E-selectin), increased serum and/or plasma concentrations of interleukin (IL)-1-β, IL-6, and tumor necrosis factor (TNF)-α, both in the peripheral blood circulation and in the central nervous system (particularly in the cerebrospinal fluid) with a higher level of consistency when measuring TNF-α and IL-6 (O'Brien et al., Journal of Psychiatric Research, 2007, 41, 326-331; Moorman et al., J. of Cardiac Failure, 2007, 13 (9), 738-43; Soygur et al., Progress in Neuro-Psychopharmacology & Biological Psychiatry, 2007, 31, 1242-1247). Additionally, allelic variants of the genes for IL-1β and TNF-α increase the risk for depression and are associated with reduced responsiveness to antidepressant therapy. Finally, there is available preclinical evidence supporting the involvement of several cytokines in models of depression and some clinical evidence of the involvement of cytokines antagonism in the treatment of depressive symptoms on patients suffering from active inflammatory diseases (Kim et al., Progress in Neuro-Psychopharmacology & Biological Psychiatry, 2007, 31, 1044-1063).

[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine (U.S. Pat. No. 7,507,737, Example 2) is a potent antagonist of the H₄ receptor (H₄R) with a K₁ of 8.4 nM and greater than 25-fold selectivity over other histamine receptors in vitro. It inhibited histamine-induced shape change of eosinophils, chemotaxis of mast cells, and IL-8 production in mast cells. In vivo, [5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine reduced inflammation in mouse models of asthma, arthritis and dermatitis. The compound also inhibited lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-α) production and other cytokines in vivo.

Based on this the evidence and the effects of H₄R antagonism it is proposed that [5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine and its chemically related family of compounds has antidepressant and/or anxiolytic properties suitable for the treatment of mood disorders (including but not limited to Major Depressive Disorder, Bipolar Disorder, Treatment Resistant Major Depressive Disorder and Treatment Resistant Bipolar Disorder), anxiety disorders, (including but not limited to Generalized Anxiety Disorder, Social Phobia, and post traumatic stress disorder). It is envisaged that H₄ antagonists will share such properties suitable for the treatment of such disorders.

Adiposity-associated inflammation and insulin resistance are associated with the development of type II diabetes, fatty liver and atherosclerosis. Macrophages are recruited into adipose tissue and atherosclerotic plaques, and are activated to release inflammatory cytokines and chemokines. High fat diets associated with the development of these conditions may lead to increased gut permeability and dyslipidemia. Consequent toll-ligand receptor, 2 and 4 (TLR2, TLR4) activation of adipocytes and macrophages by bacteria and by high levels of free fatty acids leads to an inflammatory phenotype and insulin resistance. Specifically, insulin signaling pathways may be attenuated by cytokines such as TNFa and IL-6 and activation of kinases including c-jun kinase, NKkB or PKCθ, downstream of TLR2/4 stimulation. Effects on insulin receptor signaling are potentiated by increased infiltration of monocyte/macrophages into the tissue by release of chemokines such as MCP-1.

H4R is a high affinity receptor for histamine expressed on monocyte/macrophage populations and other hematopoietic cells. Antagonism of the H4R has been shown to reduce TLR4 signaling in vitro and to reduce TLR2 and TLR4 mediated inflammatory cytokine production in vitro and in vivo. Levels of pro-inflammatory mediators including TNF-α, IL-6 and LTB4 have been variously shown to be inhibited by H4R antagonism in TLR dependent systems. Data obtained in the context of this invention support the claim that H4R antagonists have beneficial properties towards the treatment of type 2 diabetes and related metabolic disorders through inflammation reduction.

Histamine H₄ receptor antagonists have anti-inflammatory and anti-pruritic activity in animal models when given systemically. This invention also relates to the use of topical formulations of H₄ receptor antagonists for the topical treatment of dermal inflammation and pruritus. The use of topical therapies for skin conditions such as urticaria and atopic dermatitis may be preferred over systemic administration due to improved safety profiles. The topical application of an H₄ receptor antagonist, (5-chloro-1H-indol-2-yl)-(4-methyl-piperazin-1-yl)-methanone (U.S. Pat. No. 6,803,362, Example 1) was tested in the context of this invention in a mouse model of pruritus. The results support the claim that topical treatment with H₄ receptor antagonists have beneficial properties towards topical anti-pruritic treatment, and it is envisaged that they also have such properties regarding topical anti-inflammatory treatment. Topical formulation of such antagonists may have utility in both human and veterinary health.

Examples of textbooks on the subject of inflammation include: 1) Gallin, J. I.; Snyderman, R., Inflammation: Basic Principles and Clinical Correlates, 3rd ed.; Lippincott Williams & Wilkins: Philadelphia, 1999; 2) Stvrtinova, V., et al., Inflammation and Fever. Pathophysiology Principles of Diseases (Textbook for Medical Students); Academic Press; New York, 1995; 3) Cecil; et al. Textbook Of Medicine, 18th ed.; W. B. Saunders Co., 1988; and 4) Stedman's Medical Dictionary.

Background and review material on inflammation and conditions related with inflammation can be found in articles such as the following: Nathan, C., Nature 2002, 420 (6917), 846-852; Tracey, K. J., Nature 2002, 420 (6917), 853-859; Coussens, L. M., et al., Nature 2002, 420 (6917), 860-867; Libby, P., Nature 2002, 420, 868-874; Benoist, C., et al., Nature 2002, 420 (6917), 875-878; Weiner, H. L., et al., Nature 2002, 420 (8917), 879-884; Cohen, J., Nature 2002, 420 (6917), 885-891; Steinberg, D., Nature Med. 2002, 8 (11), 1211-1217.

Thus, small-molecule histamine H₄ receptor modulators according to this invention control the release of inflammatory mediators and inhibit leukocyte recruitment, and may be useful in treating inflammation of various etiologies, including the following conditions and diseases: inflammatory disorders, allergic disorders, dermatological disorders, autoimmune disease, lymphatic disorders, pruritis, and immunodeficiency disorders. Diseases, disorders and medical conditions that are mediated by histamine H₄ receptor activity include those referred to herein.

Certain diamine-substituted pyridines are described in the following publications: Intl. Pat. Appl. Publ. WO 2008/122378 (UCB Pharma, Oct. 18, 2008); Intl. Pat. Appl. Publ. WO 1991/09849 (Upjohn, Jul. 11, 1991); Intl. Pat. Appl. Publ. WO 2008/063718 (Hoffmann La Roche, Jun. 22, 2006); U.S. Pat. No. 4,788,196 (Pfizer, Nov. 29, 1988); and U.S. Pat. No. 4,806,536 (Pfizer, Feb. 21, 1989).

Certain amine-substituted 2-aminopyrimidines are disclosed in the following publications: Becker, I. J. Het. Chem. 2005, 42 (7), 1289-1295; Eur. Pat. Appl. No. EP 1437348 (Jul. 14, 2004); U.S. Pat. No. 3,907,801 (Sep. 23, 1975); Lespagnol, A. et al. Chim. Therap. 1971, 6 (2), 105-108; Willecomme, B. Annales de Chimie 1969, 4 (6 ), 405-428; Lespagnol, A. et al. Chim. Therap. 1985, 1, 26-31; Intl. Pat. Appl. Publ. WO 2001/62233 (Aug. 30, 2007); Intl. Pat. Appl. Publ. WO 2001/47921 (Jul. 5, 2001); U.S. Pat. Appl. Publ. US 2007/0167459 (One Pharmaceutical Co., Jul. 19, 2007); U.S. Pat. Appl. Publ. US 2003/0105106 (Pfizer, Jun. 5, 2003); U.S. Pat. Appl. Publ. US 2002/0147200 (Nilsson, Oct. 10, 2002); and U.S. Pat. No. 5,147,876 (Mitsui, Sep. 15, 1992).

Certain amine-substituted 2-aminopyridazines are disclosed in the following publications: Heinisch, G. Heterocycles 1999, 51 (5), 1035-1050: U.S. Pat. Appl. Publ. US 2005182067 (Amgen Inc., Aug. 18, 2005) and Intl. Pat. Appl. WO 2002/022605 (Vertex Pharmaceuticals Inc., Mar. 21, 2002). Additionally, (5-piperazin-1-yl-pyridazin-3-yl)-p-tolyl-amine (CAS No. 1092336-93-0) is commercially available.

Certain substituted 2-aminopyrimidines as histamine H₄ antagonists are disclosed in Intl. Pat. Appt. Publ. WO 2008/074445 (UCB Pharma, Jun. 26, 2008); WO 2005/054239 (Bayer Healthcare AG; Jun. 16, 2005) and EP 1505064 (Bayer Healthcare AG; Feb. 9, 2005; counterpart of Intl. Pat. Appl. Publ. WO 2005/014556). Substituted pyrimidines are described as histamine H₄ ligands in U.S. Pat. Appl. Publ. 2007/0185075 (Pharmacia Corp.; Aug. 9, 2007), Intl. Pat. Appl. Publ. WO 2007/031520 (Palau Pharma S.A.; Mar. 22, 2007), and U.S. patent application Ser. No. 12/070,051 (Feb. 14, 2008). Additional disclosures of amino pyrimidines as histamine H₄ ligands include: Intl. Pat. Appl. Publ. Nos. WO 2007/090852, WO 2007/090853, and WO 2007/090854 (Aug. 16, 2007), and EP 1767537 (Mar. 28, 2007), all reported by Cellzome Ltd., Intl. Pat. Appl. Publ. Nos. WO 2008/031556 (UCB Pharma; Mar. 20, 2008), WO 2006/050965 (Argenta; May 18, 2006), and WO 2007/072163 (Pfizer; Jun. 28, 2007).

However, there remains a need for potent histamine H₄ receptor modulators with desirable pharmaceutical properties. Certain diamino-pyridine, pyrimidine and pyridazine derivatives have been found in the context of this invention to have histamine H₄ receptor-modulating activity.

SUMMARY OF THE INVENTION

One aspect of this invention concerns compounds of Formula (I)

wherein

-   Z is CH or N; -   Y is CH or N; -   Z and Y are defined independently of each other, and the ring     containing said Y and Z members does not have more than two nitrogen     members; provided that -   i) when Y is CH and Z is CH or N, then; -   R¹ is:     -   a) —(CH₂)₂OCH₃, —CH₂)₂SCH₃, or C₁₋₈alkyl, each independently         unsubstituted or substituted with —OH or —CF₃;     -   b) —(CH₂)₀₋₂—Ar¹, —CHR²—Ar¹, or —(CH₂)₀₋₂—Ar², each of said Ar¹         and Ar² independently unsubstituted or substituted with halo,         —CH₃, or —OCH₃,     -   Ar¹ is a 6-membered aromatic carboxylic ring,     -   Ar² is a 5 to 6-membered heteroaromatic ring containing N, S or         O; or     -   c) cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CH₂)-(bridged         polycyclic cycloalkyl)₀₋₁, —(CHR²)-(monocyclic cycloalkyl),         —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged monocyclic         cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, or         —(CH₂)₀₋₁-tetrahydropyranyl, each of said cycloalkyl         independently unsubstituted or substituted with one, two, or         three C₁₋₄alkyl substituents; -   R² is -C₁₋₄alkyl;

-   where R^(a), R^(b), and R^(c) are each independently H or C₁₋₃alkyl; -   provided that: -   when R¹ is isopropyl, then R^(c) is methyl; -   when R¹ is 4-methylphenyl, then R^(c) is methyl; -   when Z is N, Y is CH, and R¹ is benzyl unsubstituted or substituted     with halo, -   then R^(c) is methyl; -   ii) when Y is H and Z is CH, then; -   R¹ is:     -   a) —(CH₂)₂OCH₃, —(CH₂)₂SCH₃, or C₁₋₈alkyl, each independently         unsubstituted or substituted with —OH or —CF₃;     -   b) —(CH₂)₀₋₂—Ar¹, —CHR²—Ar¹, —(CH₂)₀₋₂—Ar², each of said Ar¹ and         Ar² independently unsubstituted or substituted with halo, —CH₃,         —OCH₃,     -   Ar¹ is a 6-membered aromatic carbocyclic ring,     -   Ar² is a 5 to 6-membered heteroaromatic ring containing N, S or         O; or     -   c) cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CH₂)-(bridged         polycyclic cycloalkyl)₀₋₁, —(CHR²)-(monocyclic cycloalkyl),         —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged monocyclic         cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl,         —(CH₂)₀₋₁-tetrahydropyranyl, each independently unsubstituted or         substituted with one, two, or three C₁₋₄alkyl substituents; -   R² is —C₁₋₄alkyl;

where R^(a), R^(b), and R^(c) are each independently H or C₁₋₃alkyl.

Other embodiments concern chemical entities of Formula (I) where Y is CH, and Z is CH or N.

Further embodiments concern chemical entities of Formula (I) where Y is N and Z is CH.

Further embodiments are provided by pharmaceutically acceptable salts of compounds of Formula (I), pharmaceutically acceptable prodrugs of compounds of Formula (I), and pharmaceutically active metabolites of compounds of Formula (I).

In certain embodiments, the compound of Formula (I) is a compound selected from those species described or exemplified in the detailed description below.

In a further aspect, the invention relates to pharmaceutical compositions for treating a disease, disorder, or medical condition mediated by histamine H₄ receptor activity, comprising an effective amount of at least one chemical entity selected from compounds of Formula (I), pharmaceutically acceptable salts of compounds of Formula (I), pharmaceutically acceptable prodrugs of compounds of Formula (I), and pharmaceutically active metabolites of Formula (I).

Pharmaceutical compositions according to the invention may further comprise a pharmaceutically acceptable excipient.

In another aspect, the invention is directed to a method of treating a subject suffering from or diagnosed with a disease, disorder, or medical condition mediated by histamine H₄ receptor activity, comprising administering to the subject in need of such treatment an effective amount of at least one chemical entity selected from compounds of Formula (I), pharmaceutically acceptable salts of compounds of Formula (I), pharmaceutically acceptable prodrugs of compounds of Formula (I), and pharmaceutically active metabolites of compounds of Formula (I).

In certain preferred embodiments of the inventive method, the disease, disorder, or medical condition is inflammation. Inflammation herein refers to the response that develops as a consequence of histamine release, which in turn is caused by at least one stimulus. Examples of such stimuli are immunological stimuli and non-immunological stimuli.

In another aspect, the chemical embodiments of the present invention are useful as histamine H₄ receptor modulators. Thus, the invention is directed to a method for modulating histamine H₄ receptor activity, including when such receptor is in a subject, comprising exposing histamine H₄ receptor to an effective amount of at least one chemical entity selected from compounds of Formula (I), pharmaceutically acceptable salts of compounds of Formula (I), pharmaceutically acceptable prodrugs of compounds of Formula (I), and pharmaceutically active metabolites of compounds of Formula (I).

An object of the present invention is to overcome or ameliorate at least one of the disadvantages of the conventional methodologies and/or prior art, or to provide a useful alternative thereto.

Additional embodiments, features, and advantages of the invention will be apparent from the following detailed description and through practice of the invention.

DETAILED DESCRIPTION OF INVENTION AND ITS PREFERRED EMBODIMENTS

The disclosures of the publications, including but not limited to patents and patent applications, cited anywhere in any part of this specification are incorporated herein by reference in their entirety.

As used herein, the terms “including”, “containing” and “comprising” are used herein in their open, non-limiting sense.

The term “alkyl” refers to a straight- or branched-chain alkyl group having from 1 to 12 carbon atoms in the chain. Examples of alkyl groups include methyl (Me), ethyl (Et), n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl (tBu), pentyl, isopentyl, tert-pentyl, hexyl, isohexyl, and groups that in light of the ordinary skill in the art and the teachings provided herein would be considered equivalent to any one of the foregoing examples.

The term “cycloalkyl” refers to a saturated or partially saturated carbocycle, such as monocyclic, fused polycyclic, bridged monocyclic, bridged polycyclic, or spiro polycyclic carbocycle having from 3 to 12 ring atoms per carbocycle. Where the term cycloalkyl is qualified by a specific characterization, such as monocyclic, fused polycyclic, bridged polycyclic, and spiro polycyclic, then such term cycloalkyl refers only to the carbocycle so characterized. Illustrative examples of cycloalkyl groups include the following entitles, in the form of properly bonded moieties:

A “heterocycloalkyl” refers to a monocyclic, or fused, bridged, or spiro polycyclic ring structure that is saturated or partially saturated and has from 3 to 12 ring atoms per ring structure selected from carbon atoms and up to three heteroatoms selected from nitrogen, oxygen, and sulfur. The ring structure may optionally contain up to two oxo groups on carbon or sulfur ring members. Illustrative entities, in the form of properly bonded moieties, include:

The term “heteroaryl” refers to a monocyclic, fused bicyclic, or fused polycyclic aromatic heterocycle (ring structure having ring atoms selected from carbon atoms and up to four heteroatoms selected from nitrogen, oxygen, and sulfur) having from 3 to 12 ring atoms per heterocycle. Illustrative examples of heteroaryl groups include the following entitles, in the form of properly bonded moieties:

Those skilled in the art will recognize that the species of heteroaryl, cycloalkyl, and heterocycloalkyl groups listed or illustrated above are not exhaustive, and that additional species within the scope of these defined terms may also be selected.

The term “halogen” represents chlorine, fluorine, bromine, or iodine. The term “halo” represents chloro, fluoro, bromo, or iodo.

The term “substituted” means that the specified group or moiety bears one or more substituents. The term “unsubstituted” means that the specified group bears no substituents. The term “optionally substituted” means that the specified group is unsubstituted or substituted by one or more substituents. Where the term “substituted” is used to describe a structural system, the substitution is meant to occur at any valency-allowed position on the system.

Any formula given herein is intended to represent compounds having structures depicted by the structural formula as well as certain variations or forms. In particular, compounds of any formula given herein may have asymmetric centers and therefore exist in different enantiomeric forms. All optical isomers and stereoisomers of the compounds of the general formula, and mixtures thereof, are considered within the scope of the formula. Thus, any formula given herein is intended to represent a racemate, one or more enantiomeric forms, one or more diastereomeric forms, one or more atropisomeric forms, and mixtures thereof. Furthermore, certain structures may exist as geometric isomers (i.e., cis and trans isomers), as tautomers, or as atropisomers. Additionally, any formula given herein is intended to refer also to any one of hydrates, solvates, and polymorphs of such compounds, and mixtures thereof, even if such forms are not listed explicitly. In some embodiments, the solvent is water and the solvates are hydrates.

To provide a more concise description, some of the quantitative expressions given herein are not qualified with the term “about”. It is understood that, whether the term “about” is used explicitly or not, every quantity given herein is meant to refer to the actual given value, and it is also meant to refer to the approximation to such given value that would reasonably be inferred based on the ordinary skill in the art, including equivalents and approximations due to the experimental and/or measurement conditions for such given value. Whenever a yield is given as a percentage, such yield refers to a mass of the entity for which the yield is given with respect to the maximum amount of the same entity that could be obtained under the particular stoichiometric conditions. Concentrations that are given as percentages refer to mass ratios, unless indicated differently.

Reference to a chemical entity herein stands for a reference to any one of: (a) the actually recited form of such chemical entity, and (b) any of the forms of such chemical entity in the medium in which the compound is being considered when named. For example, reference herein to a compound such as R—COOH, encompasses reference to any one of, for example, R—COOH_((s)), R—COOH_((sol)), and R—COO⁻ _((sol)). In this example, R—COOH_((s)) refers to the solid compound, as it could be for example in a tablet or some other solid pharmaceutical composition or preparation; R—COOH_(sol)) refers to the undissociated form of the compound in a solvent; and R—COO⁻ _((sol)) refers to the dissociated form of the compound in a solvent, such as the dissociated form of the compound in an aqueous environment, whether such dissociated form derives from R—COOH, from a salt thereof, or from any other entity that yields R—COO⁻ upon dissociation in the medium being considered. In another example, an expression such as “exposing an entity to compound of formula R—COOH” refers to the exposure of such entity to the form, or forms, of the compound R—COOH that exists, or exist, in the medium in which such exposure takes place. In this regard, if such entity is for example in an aqueous environment, it is understood that the compound R—COOH is in such same medium, and therefore the entity is being exposed to species such as R—COOH_((aq)) and/or R—COO⁻ _((aq)), where the subscript “(aq)” stands for “aqueous” according to its conventional meaning in chemistry and biochemistry. A carboxylic acid functional group has been chosen in these nomenclature examples; this choice is not intended, however, as a limitation but it is merely an illustration. It is understood that analogous examples can be provided in terms of other functional groups, including but not limited to hydroxyl, basic nitrogen members, such as those in amines, and any other group that interacts or transforms according to known manners in the medium that contains the compound. Such interactions and transformations include, but are not limited to, dissociation, association, tautomerism, solvolysis, including hydrolysis, solvation, including hydration, protonation, and deprotonation. No further examples in this regard are provided herein because these interactions and transformations in a given medium are known by any one of ordinary skill in the art.

Any formula given herein is also intended to represent unlabeled forms as well as isotopically labeled forms of the compounds. Isotopically labeled compounds have structures depicted by the formulas given herein except that one or more atoms are replaced by an atom having a selected atomic mass or mass number. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, chlorine, and iodine, such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³¹ P, ³⁵S, ¹⁸F, ³⁶Cl, and ¹²⁵I, respectively. Such isotopically labelled compounds are useful in metabolic studies (preferably with ¹⁴C), reaction kinetic studies (with, for example ²H or ³H), detection or imaging techniques [such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT)] including drug or substrate tissue distribution assays, or in radioactive treatment of patients. In particular, an ¹⁸F or ¹¹C labeled compound may be particularly preferred for PET or SPECT studies. Further, substitution with heavier isotopes such as deuterium (i.e., ²H) may afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements. Isotopically labeled compounds of this invention and prodrugs thereof can generally be prepared by carrying out the procedures disclosed in the schemes or in the examples and preparations described below by substituting a readily available isotopically labeled reagent for a non-isotopically labeled reagent.

When referring to any formula given herein, the selection of a particular moiety from a list of possible species for a specified variable is not intended to define the same choice of the species for the variable appearing elsewhere. In other words, where a variable appears more than once, the choice of the species from a specified list is independent of the choice of the species for the same variable elsewhere in the formula, unless stated otherwise.

By way of a first example on substituent terminology, if substituent S¹ _(example) is one or S₁ and S₂, and substituent S² _(example) is one of S₃ and S₄, then these assignments refer to embodiments of this invention given according to the choices S¹ _(example) is S₁ and S² _(example) is S₁ and S² _(example) is S₄; S¹ _(example) is S₂ and S² _(example) is S₃; S¹ _(example) is S₂ and S² _(example) is S₄; and equivalents of each one of such choices. The shorter terminology “S¹ _(example) is one of S₁ and S₂, and S² _(example) is one of S₃ and S₄” is accordingly used herein for the sake of brevity, but not by way of limitation. The foregoing first example on substituent terminology, which is stated in generic terms, is meant to illustrate the various substituent assignments described herein. The foregoing convention given herein for substituents extends, when applicable, to members such as R¹⁻⁴, R^(a-c), and Z, and any other generic substituent symbol used herein.

Furthermore, when more than one assignment is given for any member or substituent, embodiments of this invention comprise the various groupings that can be made from the listed assignments, taken independently, and equivalents thereof. By way of a second example on substituent terminology, if it is herein described that substituent S_(example) is one of S₁, S₂, and S₃, this listing refers to embodiments of this invention for which S_(example) is S₁; S_(example) is S₂; S_(example) is S₃; S_(example) is one of S₁ and S₂; S_(example) is one of S₁ and S₃; S_(example) is one of S₂ and S₃; S_(example) is one of S₁, S₂ and S₃; and S_(example) is any equivalent of each one of these choices. The shorter terminology “S_(example) is one of S₁, S₂, and S₃” is accordingly used herein for the sake of brevity, but not by way of limitation. The foregoing second example on substituent terminology, which is stated in generic terms, is meant to illustrate the various substituent assignments described herein. The foregoing convention given herein for substituents extends, when applicable, to members such as R¹⁻⁴, R^(a-c), and Z, and any other generic substituent symbol used herein.

The nomenclature “C_(i-j)” with j>i, when applied herein to a class of substituents, is meant to refer to embodiments of this invention for which each and every one of the number of carbon members, from i to j including i and j, is independently realized. By way of example, the term C₁₋₃ refers independently to embodiments that have one carbon member (C₁), embodiments that have two carbon members (C₂), and embodiments that have three carbon members (C₃).

The term C_(n-m)alkyl refers to an aliphatic chain, whether straight or branched, with a total number N of carbon members in the chain that satisfies n≦N≦m, with m>n.

Any disubstituent referred to herein is meant to encompass the various attachment possibilities when more than one of such possibilities are allowed. For example, reference to disubstituent—A-B—, where A≠B—, refers herein to such disubstituent with A attached to a first substituted member and B attached to a second substituted member, and it also refers to such disubstituent with A attached to the second substituted member and B attached to the first substituted member.

According to the foregoing interpretive considerations on assignments and nomenclature, it is understood that explicit reference herein to a set implies, where chemically meaningful and unless indicated otherwise, independent reference to embodiments of such set, and reference to each and every one of the possible embodiments of subsets of the set referred to explicitly.

Some embodiments are given by compounds of Formula (I) where Y is CH, Z is CH or N, and R¹ is C₁₋₈alkyl (unsubstituted or substituted with —OH or —CF₃), phenyl, pyridyl, benzyl, pyridin-2-ylmethyl, phenylethyl, 1-phenyl-ethyl (each independently unsubstituted or substituted with halo, —CH₃, —OCH₃), cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CHR²)-(monocyclic cycloalkyl), —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged polycyclic cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, or —(CH₂)₀₋₁-tetrahydropyranyl (each independently unsubstituted or substituted with one, two, or three C₁₋₄alkyl substituents). In some of these embodiments, R¹ is 2,2-dimethylpropanol, 2,2-dimethylpropan-1-ol, 2,2-dimethylpropyl, 2-methyl-1-propan-2-ol, 2-methylpropan-2-ol, 3-propanol, (1-methylethyl), 2,2-dimethylpropyl, 2-methoxyethyl, 2-methylpropyl, 4,4,4-trifluorobutyl, propyl, butyl, tert-butyl, propan-1-ol, 2-(methylsulfanyl)ethyl, 2-phenylethyl, furan-3-ylmethyl, pyridin-2-ylmethyl, (1R)-1-phenylethyl, benzyl, phenyl, 4-fluorobenzyl, 4-methoxybenzyl, 4-methylbenzyl, bicyclo[2.2.1]hept-2-ylmethyl, tetrahydro-2H-pyran-4-yl, tetrahydrofuran-2-ylmethyl, (1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl, (1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (1S,2S,4R)-bicyclo[2.2.1]hept-2-yl, (1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (2R)-tetrahydrofuran-2-ylmethyl, (2S)-bicyclo[2.2.1]hept-2-yl], [(2S)-tetrahydrofuran-2-ylmethyl, (3R)-tetrahydrofuran-3-yl, (6,6-dimethylbicyclo[3.1.1]hept-2-yl)methyl, bicyclo[2.2.1]hept-2-yl, cyclobutyl, cyclohexyl, cyclopentyl, cyclopropyl, cyclohexylmethyl, cyclopentylmethyl, cyclopropylmethyl, adamantan-1-yl, 2-adamantyl, bicyclo[2.2.1]hept-2-yl, or (6,6-dimethyl-bicyclo[3.1.1]hept-2-yl)-methyl.

In some embodiments, where Y is CH and Z is CH or N, R¹ is

In some embodiments, where Y is CH and Z is CH or N,

is

In some embodiments, where Y is CH and Z is CH or N,

is

In some embodiments, where Y is CH and Z is CH or N,

is

In some embodiments, where Y is CH and Z is CH or N,

is

In some embodiments, where Y is CH and Z is CH or N,

is

In some embodiments, where Y is CH and Z is CH or N,

is

In some embodiments, where Y is CH and Z is CH or N, R^(a) is H.

In some embodiments, where Y is CH and Z is CH or N, R^(b) is H or methyl.

In some embodiments, where Y is CH and Z is CH or N, R^(c) is H or methyl. In some embodiments, where Y is CH and Z is CH or N, R² is —CH₃.

In some embodiments Y and Z are CH.

In some embodiments Y and Z is N.

Some further embodiments are given by compounds of Formula (I) where Y is N, Z is CH, and R¹ is C₁₋₈alkyl (unsubstituted or substituted with —OH or —CF₃), phenyl, pyridyl, benzyl pyridin-2-ylmethyl, phenylethyl, 1-phenyl-ethyl (each independently unsubstituted or substituted with halo, —CH₃, —OCH₃), cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CHR²)-(monocyclic cycloalkyl), —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged polycyclic cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, or —(CH₂)₀₋₁-tetrahydropyranyl (each independently unsubstituted or substituted with one, two, or three C₁₋₄alkyl substituents). In some of these embodiments, R¹ is 2,2-dimethylpropanol, 2,2-dimethylpropan-1-ol, 2,2-dimethylpropyl, 2-methyl-1-propan-2-ol, 2-methylpropan-2-ol, 3-propanol, (1-methylethyl), 2,2-dimethylpropyl, 2-methoxyethyl, 2-methylpropyl, 4,4,4-trifluorobutyl, propyl, butyl, tert-butyl, propan-1-ol, 2-(methylsulfanyl)ethyl, 2-phenylethyl, furan-3-ylmethyl, pyridin-2-ylmethyl, (1R)-1-phenylethyl, benzyl, phenyl, 4-fluorobenzyl, 4-methoxybenzyl, 4-methylbenzyl, bicyclo[2.2.1]hept-2-ylmethyl, tetrahydro-2H-pyran-4-yl, tetrahydrofuran-2-ylmethyl, (1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl, (1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (1S,2S,4R)-bicyclo[2.2.1]hept-2-yl, (1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (2R)-tetrahydrofuran-2-ylmethyl, (2S)-bicyclo[2.2.1]hept-2-yl], [(2S)-tetrahydrofuran-2-ylmethyl, (3R)-tetrahydrofuran-3-yl, (6,6-dimethylbicyclo[3.1.1]hept-2-yl)methyl, bicyclo[2.2.1]hept-2-yl, cyclobutyl, cyclohexyl, cyclopentyl, cyclopropyl, cyclohexylmethyl, cyclopentylmethyl, cyclopropylmethyl, adamantan-1-yl, 2-adamantyl, bicyclo[2.2.1]hept-2-yl, or (6,6-dimethyl-bicyclo[3.1.1]hept-2-yl)-methyl.

In some embodiments, where Y is N and Z is CH, R¹ is

In some embodiments, where Y is N and Z is CH,

is

In some embodiments, where Y is N and Z is CH,

is

In some embodiments, where Y is N and Z is CH,

is

In some embodiments, where Y is N and Z is CH,

is

In some embodiments, where Y is N and Z is CH,

is

In some embodiments, where Y is N and Z is CH,

is

In some embodiments, where Y is N and Z is CH, and R^(a) is H.

In some embodiments, where Y is H and Z is CH, R^(b) is H or methyl.

In some embodiments, where Y is N and Z is CH, R^(c) is H or methyl.

In some embodiments, where Y is H and Z is CH, R² is —CH₃.

In some embodiments, where Y is N and Z is CH.

The invention includes also pharmaceutically acceptable salts of the compounds represented by Formula (I), preferably of those described above and of the specific compounds exemplified herein, and methods using such salts.

A “pharmaceutically acceptable salt” is intended to mean a salt of a free acid or base of a compound represented by Formula (I) that is non-toxic, biologically tolerable, or otherwise biologically suitable for administration to the subject. See, generally, G. S. Paulekuhn, et al., “Trends in Active Pharmaceutical Ingredient Salt Selection based on Analysis of the Orange Book Database”, J. Med. Chem., 2007, 50:6665-72, S. M. Berge, et al., “Pharmaceutical Salts”, J Pharm Sci., 1977, 66:1-19, and Handbook of Pharmaceutical Salts, Properties, Selection, and Use, Stahl and Wermuth, Eds., Wiley-VCH and VHCA, Zurich, 2002. Examples of pharmaceutically acceptable salts are those that are pharmacologically effective and suitable for contact with the tissues of patients without undue toxicity, irritation, or allergic response. A compound of Formula (I) may possess a sufficiently acidic group, a sufficiently basic group, or both types of functional groups, and accordingly react with a number of inorganic or organic bases, and inorganic and organic acids, to form a pharmaceutically acceptable salt. Examples of pharmaceutically acceptable salts include sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, phosphates, monohydrogen-phosphates, dihydrogenphosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, propionates, decanoates, caprylates, acrylates, formates, isobutyrates, caproates, heptanoates, propiolates, oxalates, malonates, succinates, suberates, sebacates, fumarates, maleates, butyne-1,4-dioates, hexyne-1,6-dioates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, sulfonates, xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates, citrates, lactates, γ-hydroxybutyrates, glycolates, tartrates, methane-sulfonates, propanesulfonates, naphthalene-1-sulfonates, naphthalene-2-sulfonates, and mandelates.

If the compound of Formula (I) contains a basic nitrogen, the desired pharmaceutically acceptable salt may be prepared by any suitable method available in the art, for example, treatment of the free base with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, sulfamic acid, nitric acid, boric acid, phosphoric acid, and the like, or with an organic acid, such as acetic acid, phenylacetic acid, propionic acid, stearic acid, lactic acid, ascorbic acid, maleic acid, hydroxymaleic acid, isethionic acid, succinic acid, valeric acid, fumeric acid, malonic acid, pyruvic acid, oxalic acid, glycolic acid, salicylic acid, oleic acid, palmitic acid, lauric acid, a pyranosidyl acid, such as glucuronic acid or galacturonic acid, an alpha-hydroxy acid, such as mandelic acid, citric acid, or tartaric acid, an amino acid, such as aspartic acid, glutaric acid or glutamic acid, an aromatic acid, such as benzoic acid, 2-acetoxybenzoic acid, naphthoic acid, or cinnamic acid, a sulfonic acid, such as laurylsulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, any compatible mixture of acids such as those given as examples herein, and any other acid and mixture thereof that are regarded as equivalents or acceptable substitutes in light of the ordinary level of skill in this technology.

Where the compound of Formula (I) contains a plurality of basic nitrogens, one skilled in the art will recognize that suitable salts include salts formed with one or more equivalents of an inorganic or organic acid. In preferred embodiments of Formula (I), such salts include bis hydrochloride salts.

If the compound of Formula (I) is an acid, such as a carboxylic acid or sulfonic acid, the desired pharmaceutically acceptable salt may be prepared by any suitable method, for example, treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary or tertiary), an alkali metal hydroxide, alkaline earth metal hydroxide, any compatible mixture of bases such as those given as examples herein, and any other base and mixture thereof that are regarded as equivalents or acceptable substitutes in light of the ordinary level of skill in this technology. Illustrative examples of suitable salts include organic salts derived from amino acids, such as N-methyl-D-glucamine, lysine, choline, glycine and arginine, ammonia, carbonates, bicarbonates, primary, secondary, and tertiary amines, and cyclic amines, such as tromethamine, benzylamines, pyrrolidines, piperidine, morpholine, and piperazine, and inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum, and lithium.

The invention also relates to pharmaceutically acceptable prodrugs of the compounds of Formula (I), and treatment methods employing such pharmaceutically acceptable prodrugs. The term “prodrug” means a precursor of a designated compound that, following administration to a subject, yields the compound in vivo via a chemical or physiological process such as solvolysis or enzymatic cleavage, or under physiological conditions (e.g., a prodrug on being brought to physiological pH is converted to the compound of Formula (I)). A “pharmaceutically acceptable prodrug” is a prodrug that is non-toxic, biologically tolerable, and otherwise biologically suitable for administration to the subject. Illustrative procedures for the selection and preparation of suitable prodrug derivatives are described, for example, in “Design of Prodrugs”, ed. H. Bundgaard, Elsevier, 1985.

Examples of prodrugs include compounds having an amino acid residue, or a polypeptide chain of two or more (e.g., two, three or four) amino acid residues, covalently joined through an amide or ester bond to a free amino, hydroxy, or carboxylic acid group of a compound of Formula (I). Examples of amino acid residues include the twenty naturally occurring amino acids, commonly designated by three letter symbols, as well as 4-hydroxyproline, hydroxylysine, demosine, isodemosine, 3-methylhistidine, norvalin, beta-alanine, gamma-aminobutyric acid, citrulline homocysteine, homoserine, ornithine and methionine sulfone.

Additional types of prodrugs may be produced, for instance, by derivatizing free carboxyl groups of structures of Formula (I) as amides or alkyl esters. Examples of amides include those derived from ammonia, primary C₁₋₆alkyl amines and secondary di(C₁₋₆alkyl) amines. Secondary amines include 5- or 6-membered heterocycloalkyl or heteroaryl ring moieties. Examples of amides include those that are derived from ammonia, C₁₋₃alkyl primary amines, and di(C₁₋₂alkyl)amines. Examples of esters of the invention include C₁₋₇alkyl, C₅₋₇cycloalkyl, phenyl, and phenyl(C₁₋₆alkyl) esters. Preferred esters include methyl esters. Prodrugs may also be prepared by derivatizing free hydroxy groups using groups including hemisuccinates, phosphate esters, dimethylaminoacetates, and phosphoryloxymethyloxycarbonyls, following procedures such as those outlined in Fleisher et al., Adv. Drug Delivery Rev. 1996, 19, 115-130. Carbamate derivatives of hydroxy and amino groups may also yield prodrugs. Carbonate derivatives, sulfonate esters, and sulfate esters of hydroxy groups may also provide prodrugs. Derivatization of hydroxy groups as (acyloxy)methyl and (acyloxy)ethyl ethers, wherein the acyl group may be an alkyl ester, optionally substituted with one or more ether, amine, or carboxylic acid functionalities, or where the acyl group is an amino acid ester as described above, is also useful to yield prodrugs. Prodrugs of this type may be prepared as described in Robinson et al., J. Med. Chem. 1996, 39, 10-18. Free amines can also be derivatized as amides, sulfonamides or phosphonamides. All of these prodrug moieties may incorporate groups including ether, amine, and carboxylic acid functionalities.

The present invention also relates to pharmaceutically active metabolites of compounds of Formula (I), and uses of such metabolites in the methods of the invention. A “pharmaceutically active metabolite” means a pharmacologically active product of metabolism in the body of a compound of Formula (I) or salt thereof. Prodrugs and active metabolites of a compound may be determined using routine techniques known or available in the art. See, e.g., Bertolini et al., J. Med. Chem. 1997, 40, 2011-2016: Shan et al., J. Pharm. Sci. 1997, 86 (7), 765-767; Bagshawe, Drug Dev. Res. 1995, 34, 220-230; Bodor. Adv. Drug Res. 1984, 13, 255-331; Bundgaard, Design of Prodrugs (Elsevier Press, 1985); and Larsen, Design and Application of Prodrugs, Drug Design and Development (Krogsgaard-Larsen et al., eds., Harwood Academic Publishers, 1991).

The compounds of Formula (I) and their pharmaceutically acceptable salts, pharmaceutically acceptable prodrugs, and pharmaceutically active metabolites, whether alone or in combination, (collectively, “active agents”) of the present invention are useful as histamine H₄ receptor modulators in the methods of the invention. Such methods for modulating histamine H₄ receptor activity comprise exposing histamine H₄ receptor to an effective amount of at least one chemical entity selected from compounds of Formula (I), pharmaceutically acceptable salts of compounds of Formula (I), pharmaceutically acceptable prodrugs of compounds of Formula (I), and pharmaceutically active metabolites of compounds of Formula (I). Embodiments of this invention inhibit histamine H₄receptor activity.

Un some embodiments, the histamine H₄ receptor is in a subject diagnosed with or suffering from a disease, disorder, or medical condition mediated through histamine H₄ receptor activity, such as those described herein. Symptoms or disease states are intended to be included within the scope of “medical conditions, disorders, or diseases.”

Accordingly, the invention relates to methods of using the active agents described herein to treat subjects diagnosed with or suffering from a disease, disorder, or condition mediated through histamine H₄ receptor activity, such as inflammation. Active agents according to the invention may therefore be used as anti-inflammatory agents. Active agents according to the invention may also be used for the treatment of pain.

In some embodiments, an active agent of the present invention is administered to treat inflammation. Inflammation may be associated with various diseases, disorders, or conditions, such as inflammatory disorders, allergic disorders, dermatological disorders, autoimmune disease, lymphatic disorders, and immunodeficiency disorders, including the more specific conditions and diseases given below. Regarding the onset and evolution of inflammation, inflammatory diseases or inflammation-mediated diseases or conditions include, but are not limited to, acute inflammation, allergic inflammation, and chronic inflammation.

Treatment of inflammation according to this invention includes topical treatments. For example, topical treatments of conditions such as pruritus, urticaria, and atopic dermatitis.

Illustrative types of inflammation treatable with a histamine H₄ receptor-modulating agent according to the invention include inflammation due to any one of a plurality of conditions such as allergy, asthma, dry eye, chronic obstructed pulmonary disease (COPD), atherosclerosis, rheumatoid arthritis (see: Ohki, E. et al. Biol. Pharm. Bull. 2007, 30 (11), 2217-2220), multiple sclerosis, inflammatory bowel diseases (including colitis, Crohn's disease, and ulcerative colitis), psoriasis, pruritis, itchy skin, atopic dermatitis, urticaria (hives), ocular inflammation (e.g., post-surgical ocular inflammation), conjunctivitis, dry eye, nasal polyps, allergic rhinitis, nasal itch, scleroderma, autoimmune thyroid diseases, post-operative adhesion (See: U.S. Pat. Appl. Publ. 2007/0185163), and immune-mediated (also known as type 1) diabetes mellitus and lupus, which are characterized by excessive or prolonged inflammation at some stage of the disease. Treatment of metabolic disorders, such as type 2 diabetes, is also envisaged within the scope of this invention. Treatment of other metabolic disorders envisaged within the scope of this invention include chronic renal failure, hepatic cholestasis, and diabetes mellitus.

Other autoimmune diseases that lead to inflammation include Myasthenia gravis, autoimmune neuropathies, such as Guillain-Barré, autoimmune uveitis, autoimmune hemolytic anemia, pernicious anemia, autoimmune thrombocytopenia, temporal arteritis, anti-phospholipid syndrome, vasculitides, such as Wegener's granulomatosis, Behcet's disease, dermatitis herpetiformis, pemphigus vulgaris, vitiligio, primary biliary cirrhosis, autoimmune hepatitis, autoimmune oophoritis and orchitis, autoimmune disease of the adrenal gland, polymyositis, dermatomyositis, spondyloarthropathies, such as ankylosing spondylitis, and Sjogren's syndrome.

Pruritis treatable with a histamine H₄ receptor-modulating agent according to the invention includes that which is a symptom of allergic cutaneous diseases (such as atopic dermatitis and hives).

Treatment of mood and anxiety disorders is also envisaged within the scope of this invention. Examples of such mood disorders include major depression disorder, bipolar disorder, treatment-resistant major depression disorder, and treatment-resistant bipolar disorder. Examples of such anxiety disorders include generalized anxiety disorder, social phobia, and post traumatic stress disorder.

In other embodiments, an active agent of the present invention is administered to treat allergy, rheumatoid arthritis, asthma, autoimmune diseases, or pruritis.

Thus, the active agents may be used to treat subjects diagnosed with or suffering from a disease, disorder, or condition mediated through histamine H₄ receptor activity. The term “treat” or “treating” as used herein is intended to refer to administration of an active agent or composition of the invention to a subject for the purpose of effecting a therapeutic or prophylactic benefit through modulation of histamine H₄ receptor activity. Treating includes reversing, ameliorating, alleviating, inhibiting the progress of, lessening the severity of, or preventing a disease, disorder, or condition, or one or more symptoms of such disease, disorder or condition mediated through modulation of histamine H₄ receptor activity. The term “subject” refers to a mammalian patient in need of such treatment, such as a human. Some embodiments of this invention are envisaged for veterinary use. “Modulators” include both inhibitors and activators, where “inhibitors” refer to compounds that decrease, prevent, inactivate, desensitize or down-regulate histamine H₄ receptor expression or activity, and “activators” are compounds that increase, activate, facilitate, sensitize, or up-regulate histamine H₄ receptor expression or activity.

In treatment methods according to the invention, an effective amount of at least one active agent according to the invention is administered to a subject suffering from or diagnosed as having such a disease, disorder, or condition. An “effective amount” means an amount or dose sufficient to generally bring about the desired therapeutic or prophylactic benefit in patients in need of such treatment for the designated disease, disorder, or condition. Effective amounts or doses of the active agents of the present invention may be ascertained by routine methods such as modeling, dose escalation studies or clinical trials, and by taking into consideration routine factors, e.g., the mode or route of administration or drug delivery, the pharmacokinetics of the agent, the severity and course of the disease, disorder, or condition, the subject's previous or ongoing therapy, the subject's health status and response to drugs, and the judgment of the treating physician. An exemplary dose is in the range of from about 0.001 to about 200 mg of active agent per kg of subject's body weight per day, preferably about 0.05 to 100 mg/kg/day, or about 1 to 35 mg/kg/day, or about 0.1 to 10 mg/kg daily in single or divided dosage units (e.g., BID, TID, QID), For a 70-kg human, an illustrative range for a suitable dosage amount is from about 1 to 200 mg/day, or about 5 to 50 mg/day.

Once improvement of the patient's disease, disorder, or condition has occurred, the dose may be adjusted for preventative or maintenance treatment. For example, the dosage or the frequency of administration, or both, may be reduced as a function of the symptoms, to a level at which the desired therapeutic or prophylactic effect is maintained. Of course, if symptoms have been alleviated to an appropriate level, treatment may cease. Patients may, however, require intermittent treatment on a long-term basis upon any recurrence of symptoms.

In addition, the active agents of the invention may be used in combination with additional active ingredients in the treatment of the above conditions. The additional active ingredients may be coadministered separately with an active agent of Formula (I) or included with such an agent in a pharmaceutical composition according to the invention. In an exemplary embodiment, additional active ingredients are those that are known or discovered to be effective in the treatment of conditions, disorders, or diseases mediated by histamine H₄ receptor activity, such as another histamine H₄ receptor modulator or a compound active against another target associated with the particular condition, disorder, or disease. The combination may serve to increase efficacy (e.g., by including in the combination a compound potentiating the potency or effectiveness of an agent according to the invention), decrease one or more side effects, or decrease the required dose of the active agent according to the invention.

When referring to modulating the target receptor, an “effective amount” means an amount sufficient to affect the activity of such receptor. Measuring the activity of the target receptor may be performed by routine analytical methods. Target receptor modulation is useful in a variety of settings, including assays.

The active agents of the invention are used, alone or in combination with one or more additional active ingredients, to formulate pharmaceutical compositions of the invention. A pharmaceutical composition of the invention comprises: (a) an effective amount of at least one active agent in accordance with the invention; and optionally (b) a pharmaceutically acceptable excipient.

A “pharmaceutically acceptable excipient” refers to a substance that is non-toxic, biologically tolerable, and otherwise biologically suitable for administration to a subject, such as an inert substance, added to a pharmacological composition or otherwise used as a vehicle, carrier, or diluent to facilitate administration of a agent and that is compatible therewith. Examples of excipients include calcium carbonate, calcium phosphate, various sugars and types of starch, cellulose derivatives, gelatin, vegetable oils, and polyethylene glycols.

Delivery forms of the pharmaceutical compositions containing one or more dosage units of the active agents may be prepared using suitable pharmaceutical excipients and compounding techniques known or that become available to those skilled in the art. The compositions may be administered in the inventive methods by a suitable route of delivery, e.g., oral, parenteral, rectal, topical, or ocular routes, or by inhalation.

The preparation may be in the form of tablets, capsules, sachets, dragees, powders, granules, lozenges, powders for reconstitution, liquid preparations, or suppositories. Preferably, the compositions are formulated for intravenous infusion, topical administration, or oral administration.

For oral administration, the active agents of the invention can be provided in the form of tablets or capsules, or as a solution, emulsion, or suspension. To prepare the oral compositions, the active agents may be formulated to yield a dosage of, e.g., from about 0.05 to about 50 mg/kg daily, or from about 0.05 to about 20 mg/kg daily, or from about 0.1 to about 10 mg/kg daily.

Oral tablets may include the active ingredient(s) mixed with compatible pharmaceutically acceptable excipients such as diluents, disintegrating agents, binding agents, lubricating agents, sweetening agents, flavoring agents, coloring agents and preservative agents. Suitable inert fillers include sodium and calcium carbonate, sodium and calcium phosphate, lactose, starch, sugar, glucose, methyl cellulose, magnesium stearate, mannitol, sorbitol, and the like. Exemplary liquid oral excipients include ethanol, glycerol, water, and the like. Starch, polyvinyl-pyrrolidone (PVP), sodium starch glycolate, microcrystalline cellulose, and alginic acid are exemplary disintegrating agents. Binding agents may include starch and gelatin. The lubricating agent, if present, may be magnesium stearate, stearic acid or talc. If desired, the tablets may be coated with a material such as glyceryl monostearate or glyceryl distearate to delay absorption in the gastrointestinal tract, or may be coated with an enteric coating.

Capsules for oral administration include hard and soft gelatin capsules. To prepare hard gelatin capsules, active ingredient(s) may be mixed with a solid, semi-solid, or liquid diluent. Soft gelatin capsules may be prepared by mixing the active ingredient with water, an oil such as peanut oil or olive oil, liquid paraffin, a mixture of mono and di-glycerides of short chain fatty acids, polyethylene glycol 400, or propylene glycol.

Liquids for oral administration may be in the form of suspensions, solutions, emulsions or syrups or may be lyophilized or presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid compositions may optionally contain: pharmaceutically-acceptable excipients such as suspending agents (for example, sorbitol, methyl cellulose, sodium alginate, gelatin, hydroxyethylcellulose, carboxymethylcellulose, aluminum stearate gel and the like); non-aqueous vehicles, e.g., oil (for example, almond oil or fractionated coconut oil), propylene glycol, ethyl alcohol, or water; preservatives (for example, methyl or propyl p-hydroxybenzoate or sorbic acid); wetting agents such as lecithin; and, if desired, flavoring or coloring agents.

The active agents of this invention may also be administered by non-oral routes. For example, compositions may be formulated for rectal administration as a suppository. For parenteral use, including intravenous, intramuscular, intraperitoneal, or subcutaneous routes, the agents of the invention may be provided in sterile aqueous solutions or suspensions, buffered to an appropriate pH and isotonicity or in parenterally acceptable oil. Suitable aqueous vehicles include Ringer's solution and isotonic sodium chloride. Such forms may be presented in unit-dose form such as ampules or disposable injection devices. In multi-dose forms such as vials from which the appropriate dose may be withdrawn, or in a solid form or pre-concentrate that can be used to prepare an injectable formulation. Illustrative infusion doses range from about 1 to 1000 μg/kg/minute of agent admixed with a pharmaceutical carrier over a period ranging from several minutes to several days.

For topical administration, the agents may be mixed with a pharmaceutical carrier at a concentration of about 0.1% to about 10% of drug to vehicle. Another mode of administering the agents of the invention may utilize a patch formulation to affect transdermal delivery.

Active agents may alternatively be administered in methods of this invention by inhalation, via the nasal or oral routes, e.g., in a spray formulation also containing a suitable carrier.

Exemplary chemical entities useful in methods of the invention will now be described by reference to illustrative synthetic schemes for their general preparation below and the specific examples that follow. Artisans will recognize that, to obtain the various compounds herein, starting materials may be suitably selected so that the ultimately desired substituents will be carried through the reaction scheme with or without protection as appropriate to yield the desired product. Alternatively, it may be necessary or desirable to employ, in the place of the ultimately desired substituent, a suitable group that may be carried through the reaction scheme and replaced as appropriate with the desired substituent. Each of the reactions depicted in Scheme A is preferably run at a temperature from about room temperature to the reflux temperature of the organic solvent used. Unless otherwise specified, the variables are as defined above in reference to Formula (I).

As shown in Scheme A, compounds of Formula (I) are prepared by sequential reaction of compounds (X) with amines (XI) and amines (XIII). Where Y and Z are CH, Hal¹ is chloro, and Hal² is chloro, bromo, or iodo, addition of amines (XI) by palladium-catalyzed amination gives compounds (XII). Amination reactions are performed in the presence of a palladium(0) catalyst such as tris(dibenzylidene-acetone)dipalladium(0) (Pd₂(dba)₃), or tetrakis(triphenylphosphine)palladium, a ligand such as 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (X-Phos), 1,1′-bis(diphenylphosphino)ferrocene (dppf), 2,2′-bis(diphenylphosphino)-1,1′-bihaphthyl (BINAP), Cy-MAP [(2′-dicyclohexylphosphanylbiphen-2-yl)dimethylamine], Cy₂P(Ph-Ph) (dicyclohexyl-2-biphenylphosphane), tBu₂P(Ph-Ph) (di-tert-butyl-2-biphenylphosphane), tBu₃P, or IPr.HCl (IPr=1,4-bis(2,6-diisopropyl)imidazol-2-ylidene), and a base such as sodium tert-butoxide, potassium tert-butoxide, lithium or sodium bis(trimethylsilyl)amide, or Cs₂CO₃, in a solvent such as toluene, tetrahydrofuran (THF), dimethylacetamide (DMA), dimethoxyethane (DME), or tert-butanol, or a mixture thereof, at a temperature from about 50° C. to about 140° C. (Ji et al. J. Org. Chem. 2003, 24, 4611-4614). Preferably, reactions are performed using Pd₂(dba)₃, Xantphos, and sodium tert-butoxide, in toluene, at a temperature of about 70° C. to about 110° C.

Compounds (XII) where Y and Z are CH and Hal¹ is chloro are subsequently converted to pyridines of Formula (I) by palladium-catalyzed animation with amines (XIII), as described above. Preferably, reactions are performed using palladium(II) acetate (Pd(OAc)₂), BINAP, and sodium tert-butoxide, in toluene, DMA, or tert-butanol (or a mixture thereof), at a temperature of about 50° C. to about 110° C.

Where Y is CH and Z is N, Hal¹ is chloro, and Hal² is chloro, bromo, or iodo, compounds (X) are reacted by displacement with amines (XI), with or without the presence of a tertiary amine base (such as diisopropylethylamine or triethylamine), in an organic solvent such as methanol, ethanol, isopropanol, tert-amyl alcohol, pentan-1-ol, THF, or acetonitrile, or a mixture thereof, at a temperature of about 0° C. to about 180° C., either by traditional heating or under microwave conditions to provide compounds of formula (XII). Compounds (XII) where Y is CH and Z is N and Hal¹ is chloro are subsequently reacted with amines (XIII) using displacement conditions as described to provide pyrimidines of Formula (I).

Additionally, compounds of Formula (I) are prepared by sequential reaction of compounds (X) with amines (XI) and amines (XIII). Compounds (X) where Y is N and Z is CH, Hal¹ and Hal² are chloro, are reacted with amines), with or without the presence of a tertiary amine base (such as diisopropylethylamine or triethylamine), in a solvent such as THF or DMF and the like, at a temperature of about 23° C. to about 110° C., to provide compounds (XII). Addition of amines (XIII) either by palladium-catalyzed amination, as described, or by displacement of the chlorine with the amine (XIII) neat or in a polar solvent such as DME, with or without the presence of a tertiary amine base (such as diisopropylethylamine or triethylamine) at temperatures ranging from 100° C. to 250° C. under conventional heating or microwave conditions, provides pyridazines of Formula (I).

As shown in Scheme B, compounds of Formula (I) are prepared by sequential reaction of compounds (XIV) with amines (XIII) and amines (XI). Compounds (XIV) where Y and Z are CH, Hal³ is fluoro and Hal⁴ is iodo or bromo, are reacted with amines (XIII) in a polar solvent such as N-methylpyrrolidinone (NMP), N,N-dimethylformamide, DMA, dimethylsulfoxide, or a mixture thereof, at a temperature of about 50° C. to about 110° C., either by traditional heating or under microwave conditions to provide compounds (XV). Addition of amines (XI) either by palladium-catalyzed amination (as described for Scheme A) or by nucleophilic aromatic substitution in the presence of a Lewis acid such as ytterbium trifluormethanesulfonate (Yb(OTf)₃), in a polar solvent such as DMA or NMP, at a temperature of about 150°0 C. to about 250° C. under conventional heating or microwave conditions, provides pyridines of Formula (I).

Compounds (XIV) where Y is CH and Z is N, Hal³ is chloro, and Hal⁴ is chloro, are reacted by displacement with amines (XIII) to give compounds (XV) and then with amines (XI) to give pyrimidines of Formula (I). Displacement reactions are performed as described for Scheme A.

As shown in Scheme C, compounds (XVII), where Y is N, Z is C, and Hal¹ is chloro, are prepared by chlorination of compounds (XVI) using conditions know to one skilled in the art, for example, by reaction with phosphoryl chloride, at temperatures ranging from 65° C. to about 120° C. afford compounds (XVII). Compounds (XVII) are reacted by displacement with amines (XI), with a tertiary amine base (such as diisopropylethylamine or triethylamine), in an organic solvent such as methanol, ethanol, isopropanol, tert-amyl alcohol, pentan-1-ol, THF, or acetonitrile, or a mixture thereof, at a temperature of about 23° C. to 180° C., either by traditional heating or under microwave conditions. Compounds (XVIII) are subsequently reacted with amines (XIII) using displacement conditions as described to provide pyridazines (XIX). Reaction of halo-pyridazines (XIX) with a reducing agent such as 10% palladium on carbon, in the presence of ammonium formate, in a polar solvent such as methanol, at temperatures ranging from 65° C. to 85° C. provides compounds of Formula (I).

As shown in Scheme D, compounds (XVI), where Y is N, Z is C, and Hal¹ is chloro, are reacted with hydrogen iodide acid (57%), at temperatures ranging from 100° C. to 150° C. to provide 5-iodo-4H-pyridazin-3one intermediate (XXI). Subsequent reaction of intermediate (XXI) with amines (XI) in a displacement fashion, in an organic solvent such as methanol, ethanol, isopropanol, tert-amyl alcohol, pentan-1-ol, THF, or acetonitrile, or a mixture thereof, at a temperatures ranging from 23° C. to 180° C., either by traditional heating or under microwave heating provide compounds of formula (XXII). Chlorination of compounds (XXII) using conditions known to one skilled in the art, for example, by reaction with phosphoryl chloride, at temperatures ranging from 65° C. to about 120° C. afford compounds (XXIII). Compounds (XXIII) are reacted with amines (XIII) in a displacement reaction, in an organic solvent such as methanol, ethanol, isopropanol, tert-amyl alcohol, pentan-1ol, THF, or acetonitrile, or a mixture thereof, at a temperature of about 23° C. to 200° C., either by traditional heating or under microwave heating provide compounds of Formula (I).

In the above Schemes, where the diamine HNR³R⁴ (XIII) contains a nitrogen protecting group (PG), such as a tert-butoxycarbonyl (Boc) group or benzyl group, in place of the R^(a) or R^(c) substituent, the protecting group is removed by deprotection conditions known to one skilled in the art, to provide compounds where R^(a) or R^(c) is H. For example, a tert-butoxycarbonyl group is removed using an organic acid such as TFA (neat or in a solvent such as CH₂Cl₂) or an inorganic acid such as HCl (in a solvent such as 1,4-dioxane, ether, methanol, isopropanol, or formic acid, or a mixture thereof). Reductive amination or alkylation procedures may be used to convert compounds where R^(c) is H to compounds where R^(c) is C₁₋₃alkyl.

Compounds of Formula (I) may be converted to their corresponding salts using methods described in the art. For example, an amine of Formula (I) is treated with trifluoroacetic acid, HCl, or citric acid in a solvent such as Et₂O, CH₂Cl₂, THF, MeOH, chloroform, or isopropanol to provide the corresponding salt form. Alternately, trifluoroacetic acid or formic acid salts are obtained as a result of reverse phase HPLC purification conditions. Crystalline forms of pharmaceutically acceptable salts of compounds of Formula (I) may be obtained in crystalline form by recrystallization from polar solvents (including mixtures of polar solvents and aqueous mixtures of polar solvents) or from non-polar solvents (including mixtures of non-polar solvents).

Compounds prepared according to the schemes described above may be obtained as single enantiomers, diastereomers, or regioisomers, by enantio-, diastero-, or regiospecific synthesis, or by resolution. Compounds prepared according to the schemes above may alternately be obtained as racemic (1:1) or non-racemic (not 1:1) mixtures or as mixtures of diastereomers or regioisomers. Where racemic and non-racemic mixtures of enantiomers are obtained, single enantiomers may be isolated using conventional separation methods known to one skilled in the art, such as chiral chromatography, recrystallization, diastereomeric salt formation, derivetization into diastereomeric adducts, biotransformation, or enzymatic transformation. Where regioisomeric or diastereomeric mixtures are obtained, single isomers may be separated using conventional methods such as chromatography or crystallization.

The following specific examples are provided to further illustrate the invention and various preferred embodiments.

EXAMPLES

In obtaining the compounds described in the examples below and the corresponding analytical data, the following experimental and analytical protocols were followed unless otherwise indicated.

Unless otherwise stated, reaction mixtures were magnetically stirred at room temperature (rt) under a nitrogen atmosphere. Where solutions are “dried,” they are generally dried over a drying agent such as Na₂SO₄ or MgSO₄. Where mixtures, solutions, and extracts were “concentrated”, they were typically concentrated on a rotary evaporator under reduced pressure-Silica gel (SiO₂) was used for flash chromatographic purification (FCC) and the eluent used is listed in parentheses.

Microwave heating was performed on a Personal Chemistry Emrys™ Optimizer using Blotage microwave vials.

Analytical reversed-phase high-performance liquid chromatography (HPLC) was performed on a Hewlett Packard HPLC Series 1100, with a Phenomenex ONYX® monolithic C18 (5 μm, 4.6×100 mm) column. Defection was done at λ=230, 254 and 280 nm. The flow rate was 1 mL/min. The gradient was 10 to 90% acetonitrile/water (20 mM NH₄OH) over 5.0 min. Preparative reversed-phase HPLC was performed on a Dionex Instrument equipped with a YMC Pack ODS 250×30 mm column with a gradient of 10 to 50% NH₄OH in acetonitrile (0.05% water) over 15 min at a flow rate of 70 mL/min. Alternatively, compounds were purified on a Waters LC/MS equipped with a Waters XBridge C18 column (100×30 mm) with a gradient of 1 to 25% actonitrile/water (0.05% trifluoroacetic acid (TFA)) over 15 min at a flow rate of 44 mL/min. Analytical reversed-phase HPLC was performed on Agilent HPLC with C18 (5 ∥m, 4.6×150 mm) column. Detection was done at λ=214 and 254 nm. The flow rate was 1 mL/min. The gradient was 10 to 90% acetonitrile/water (0.1% formic Acid) over 10 min.

Preparative thin-layer chromatography (TLC) was performed using 20×20 cm silica gel 60 F₂₅₄ plates, with a 0.5 mm thickness.

Preparative reversed-phase HPLC was performed on Gemini column C18 (150×21.2 mm) with a gradient of 5 to 60% acetonitrile and water (0.1% trifluoroacetic acid or 0.1% formic acid) over 14 min at a flow rate 20 mL/min monitored at 214 nm.

Compounds were analyzed in a free-base, hydrochloride of trifluoroacetate salt form. Hydrochloride salts were obtained either: 1) during the removal of the tert-butylcarbamoyl (Boc) group; or 2) by treatment of a solution of the purified free base in THF, CHCl₃ or CH₂Cl₂ (DCM) with at least two equivalents of a solution of HCl in 1,4-dioxane or ether followed by concentration. TFA salts were obtained directly from HPLC purification.

Nuclear magnetic resonance (NMR) spectra were obtained on Bruker model DRX spectrometers (400 MHz or 500 MHz) or Varian (300 MHz) spectrometer. The format of the ¹H NMR data below is: chemical shift in ppm downfield of the tetramethylsilane reference (multiplicity, coupling constant J in Hz, integration).

Mass spectra were obtained on an Agilent series 1100 USD or 1200 MSD using electrospray ionization (ESI) in either positive or negative modes as indicated. The MS data presented is the m/z found (typically [M+H]⁺) for the molecular ion.

Chemical names were generated using ACD/Name Version 10 (Advanced Chemistry Development, Toronto, Ontario, Canada) or ChemDraw Version 6.0.2 (CambridgeSoft, Cambridge, Mass.),

Example 1 Bicyclo[2.2.1]hept-2-yl[4-((3R)-3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]amine dihydrochloride

(3R)-[1-(2-Chloro-pyridin-4-yl)-pyrrolidin-3-yl]-methyl-amine. To a stirring solution of 2-chloro-4-bromopyridine (4.3 g, 22.1 mmol) in toluene (100 mL) was added (R)-methyl-pyrrolidin-3-yl-amine (1.7 g, 17.0 mmol) and sodium tert-butoxide (2.5 g, 26.0 mmol). The flask was evacuated and flushed with N_(2(g)) twice. A mixture of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos; 590 mg, 1.0 mmol) and tris(dibenzylideneacetone)-dipalladium(0) (Pd₂(dba)₃; 310 mg, 0.34 mmol) was added in one portion and the mixture was heated at 85° C. for 20 h. The mixture was cooled to room temperature (rt), diluted with H₂O (75 mL), and extracted with ethyl acetate (EtOAc; 3×). The combined organic layers were dried and concentrated to give a clear brown oil. The oil was purified by FCC (0 to 5% 2 M NH₃ in MeOH/CH₂Cl₂) to give the title compound as a brown solid (1.1 g, 30%). MS (ESI): mass calcd. for C₁₀H₁₄ClN₃, 211.09 m/z found, 212.1 [M+H]. ¹H NMR (DMSO-d₆): 7.86 (d, J=5.9, 1H), 6.47-6.38 (m, 2H), 3.45-3.17 (m, 4H), 3.11-3.01 (m, 1H), 2.29 (s, 3H), 2.15-2.00 (m, 1H), 1.82 (br s, 1H), 1.79-1.65 (m, 1H). Bicyclo[2.2.1]hept-2-yl-[(3R)-4-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine. To a stirring mixture of [(3R)-1-(2-chloro-pyridin-4-yl)-pyrrolidin-3-yl]-methyl-amine (97 mg, 0.46 mmol), exo-2-aminonorbornane (164 μL, 1.4 mmol) in ethylene glycol dimethyl ether (DME; 4 mL) in a scintillation vial was added sodium tert-butoxide (245 mg, 2.6 mmol). To the stirring mixture was added in one portion Pd(OAc)₂ (16 mg, 0.024 mmol) and racemic 2,2′-bis(diphenylphosphino)-1,1′-bihaphthyl (BINAP: 19 mg, 0.031 mmol). The mixture was heated at 65° C. for 20 h, then was cooled to rt and filtered through a plug of diatomaceous earth. The plug was washed with MeOH (2 mL) and the filtrate was purified directly by FCC (5% 2 M NH₃ in MeOH/CH₂Cl₂) to give a clear light golden oil (70 mg, 54%). Bicyclo[2.2.1]hept-2-yl[(3R)-4-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine. To a stirring solution of bicyclo[2.2.1]hept-2-yl-[(3R)-4-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine in 1:1 Et₂O/CH₂Cl₂ (8 mL) was added 1 N HCl in Et₂O (1 mL). The organic layers was separated and concentrated to give the desired product (89 mg, 100%) as a beige solid. MS (ESI): mass calcd. for C₁₇H₂₆N₄, 286.2; m/z found, 287.3 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.07 (s, 1H), 9.57 (br s, 1H), 9.46 (br s, 1H), 7.81 (d, J=5.1, 1H), 7.66 (d, J=4.6, 1H), 6.28 (d, J=7.4, 1H), 5.64 (s, 1H), 3.89 (br s, 1H), 3.85-3.61 (m, 3H), 3.49 (br s, 2H), 2.60 (s, 3H), 2.35-2.20 (m, 3H), 2.18 (s, 1H), 1.95-1.85 (m, 1H), 1.55-1.46 (m, 3H), 1.37-1.25 (m, 2H), 1.21-1.09 (m: 2H).

The compounds in Example 2 through Example 15 were prepared using methods analogous to those described for Example 1.

Example 1 N-Cyclopentyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.2; m/z found, 261.3 [M+H]⁺. ¹H NMR (DMSO-d₆): 7.57 (d, J=5.9, 1H), 5.77 (dd, J=5.9, 2.1, 1H), 5.72 (d, J=7.1, 1H), 5.42 (s, 1H), 4.05-3.96 (m, 1H), 3.36-3.29 (m, 2H), 3.28-3.15 (m, 2H), 2.99-2.91 (m, 1H), 2.29 (s, 3H), 2.06-1.98 (m, 1H), 1.90-1.81 (m, 2H), 1.81-1.72 (m, 2H), 1.71-1.82 (m, 2H), 1.55-1.46 (m, 2H), 1.45-1.35 (m, 2H).

Example 3 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-propylpyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₃H₂₂N₄, 260.2; m/z found, 235.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.12 (s, 1H), 9.46-9.26 (m, 2H), 7.71 (d, J=5.2, 1H), 7.65 (d, J=6.9, 1H), 6.29 (d, J=7.4, 1H), 5.68 (s, 1H), 3.90 (br s, 1H), 3.78-3.61 (m, 3H), 3.37 (br s, 1H), 3.28-3.16 (m, 2H), 2.61 (s, 3H), 2.46-2.21 (m, 2H), 1.58 (q, J=7.3, 2H), 0.95 (t, J=7.4, 3H).

Example 4 N-(Cyclopropylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine ditrifluoroacetate

MS (ESI): mass calcd. for C₁₄H₂₂N₄, 246.2; m/z found, 247.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.00 (s, 1H), 8.96 (s, 2H), 7.74 (d, J=5.1, 1H), 7.66 (d, J=4.3, 1H), 6.30 (d, J=7.4, 1H), 5.71 (s, 1H), 3.94 (br s, 2H), 3.60 (br s, 2H), 3.12 (d, J=6.8, 2H), 2.67 (s, 3H), 2.51-2.42 (m, 2H), 2.42-2.36 (m, 1H), 1.58-1.46 (m, 1H), 0.53 (d, J=8.0, 2H), 0.27 (d, J=6.1, 2H).

Example 5 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(3R)-tetrahydrofuran-3-yl]pyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₄H₂₂N₄O, 262.2; m/z found, 263.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.14 (s, 1H), 9.55 (br s, 1H), 9.48 (s, 1H), 7.90 (d, J=7.1, 1H), 7.68 (d, J=7.1, 1H), 7.48 (s, J=8.0, 0.5H), 7.12 (d, J=8.4, 0.5H), 6.32 (d, J=7.4, 1H), 5.73 (s, 1H), 4.35-4.21 (m, 1H), 3.95-3.79 (m, 3H), 3.82-3.70 (m, 2H), 3.66-3.50 (m, 2H), 2.61 (t J=5.1, 3H), 2.45-2.21 (m, 4H), 1.88-1.74 (m, 1H).

Example 6 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[tetrahydrofuran-2-ylmethyl]pyridin-2-amine dihydrochloride

The title compound was prepared as a mixture of diastereomers. MS (ESI): mass calcd. for C₁₅H₂₄N₄O, 276.2; m/z found, 277.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.34 (s, 1H), 9.63 (br s, 1H), 9.60 (s, 1H), 7.75-7.61 (m, 2H), 6.27 (d, J=7.4, 1H), 5.77 (s, 1H), 4.05-3.96 (m, 1H), 3.96-3.83 (m, 1H), 3.82-3.61 (m, 6H), 3.38-3.30 (m, 2H), 2.58 (s, 3H), 2.48-2.38 (m, 2H), 2.04-1.85 (m, 3H), 1.78-1.72 (m, 1H).

Example 7 N-(4-Fluorobenzyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₇H₂₁FN₄, 300.2; m/z found, 301.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.39 (s, 1H), 9.38 (br s, 2H), 8.15 (t, J=6.0, 1H), 7.68 (d, J=7.1, 1H), 7.48-7.38 (m, 2H), 7.25-7.13 (m, 2H), 6.29 (d, J=7.4, 1H), 5.73 (s, 1H), 4.52 (d, J=6.0, 2H), 3.96 (br s, 1H), 3.92-3.38 (m, 4H), 2.59 (s, 3H), 2.42-2.21 (m, 2H).

Example 8 N-Cyclopropyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₃H₂₀N₄, 232.2; m/z found, 233.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.21 (s, 1H), 9.58 (br s, 2H), 8.28 (d, J=5.4, 0.35H), 8.19 (s, 1H), 7.70 (s, 0.65H), 6.90 (d, J=7.4, 0.66H), 6.35 (d, J=7.4, 0.65H), 5.78 (s, 1H), 4.02-3.33 (m, 6H), 2.60 (s, 3H), 2.43-2.25 (m, 2H), 0.88-0.86 (m, 2H), 0.56-0.50 (m, 2H).

Example 9 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5; m/z found, 329.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.56 (d, J=6.2, 1H), 5.93 (dd, J=6.2, 2.2, 1H), 5.56 (d, J=2.1, 1H), 4.80 (s, 4H), 3.99 (dt, J=9.4, 6.3, 1H), 3.52 (dd, J=10.0, 6.4, 1H), 3.49-3.40 (m, 1H), 3.38-3.27 (m, 4H), 3.11 (dd, J=10.0, 5.2, 1H), 2.71-2.61 (m, 1H), 2.46-2.37 (m, 1H), 2.23 (td, J=13.6, 5.9, 1H), 2.01-1.77 (m, 4H), 1.58 (ddd, J=13.8, 5.6, 2.4, 1H), 1.24 (d, J=8.9, 3H), 1.13 (t, J=7.4, 3H), 1.10 (s, 3H), 1.03 (d, J=9.7, 1H).

Example 10 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5; m/z found, 329.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.56 (d, J=6.2, 1H), 5.95 (dd, J=6.3, 2.2, 1H), 5.57 (d, J=2.1, 1H), 3.99 (dt, J=9.4, 6.3, 1H), 3.52 (dd, J=10.0, 6.3, 1H), 3.46 (dd, J=14.7, 8.9, 1H), 3.39-3.28 (m, 6H), 3.13 (dd, J=10.0, 5.1, 1H), 2.67 (t, J=11.6, 1H), 2.47-2.37 (m, 1H), 2.23 (td, J=13.7, 5.9, 1H), 2.02-1.78 (m, 4H), 1.58 (ddd, J=13.8, 5.6, 2.4, 1H), 1.26 (s, 3H), 1.14 (d, J=7.2, 3H), 1.10 (s, 3H), 1.03 (d, J=9.7, 1H).

Example 11 N-Benzyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₂N₄, 282.4; m/z found, 283.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.57 (d, J=6.1, 1H), 7.36-7.32 (m, 2H), 7.31-7.26 (m, 2H), 7.20 (t, J=7.2, 1H), 5.93 (dd, J=6.2, 2.2, 1H), 5.51 (d, J=2.1, 1H), 4.41 (s, 2H), 3.44 (dd, J=10.0, 6.4, 1H), 3.41-3.32 (m, 1H), 3.28-3.19 (m, 1H), 3.04 (dd, J=10.0, 5.1, 1H), 2.27-2.10 (m, 1H), 1.93-1.76 (m, 1H).

Example 12 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(1-methylethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₂N₄, 234.4; m/z found, 235.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.56 (d, J=6.2, 1H), 5.92 (dd, J=6.2, 2.2, 1H), 5.53 (d, J=2.1, 1H), 3.82 (hept, J=6.4, 1H), 3.51 (dd, J=10.0, 6.4, 1H), 3.48-3.40 (m, 1H), 3.38-3.26 (m, 2H), 3.10 (dd, J=10.0, 5.2, 1H), 2.27-2.17 (m, 1H), 1.96-1.79 (m, 1H), 1.18 (d, J=6.4, 6H).

Example 13 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(1-methylethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₀N₄, 220.3; m/z found, 221.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.55 (d, J=7.4, 1H), 6.35 (dd, J=7.4, 2.4, 1H), 5.74 (d, J=2.3, 1H), 4.12 (s, 1H), 3.83 (dt, J=12.7, 6.4, 2H), 3.78-3.66 (m, 1H), 3.68-3.54 (m, 2H), 3.40-3.24 (m, 4H), 2.53 (dd, J=14.9, 6.5, 1H), 2.26 (d, J=5.3, 1H), 1.28 (d, J=6.4, 6H).

Example 14 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₂N₄, 234.4; m/z found, 235.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.49 (d, J=7.3, 1H), 6.23 (dd, J=7.3, 2.4, 1H), 5.64 (d, J=2.3, 1H), 3.78-3.69 (m, 1H), 3.66-3.56 (m, 2H), 3.51-3.41 (m, 1H), 3.33-3.27 (m, 1H), 3.20 (dd, J=10.8, 4.5, 1H), 3.06 (d, J=6.9, 2H), 2.32-2.20 (m, 1H), 1.97-1.85 (m, 2H), 1.01 (d, J=8.7, 6H).

Example 15 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₄N₄, 248.4; m/z found, 249.2 [M+H]⁺. ¹H NMR CD₃OD): 7.55 (d, J=6.4, 1H), 6.02 (dd, J=6.5, 2.2, 1H), 5.57 (d, J=2.1, 1H), 3.56 (dd, J=10.2, 6.3, 1H), 3.53-3.46 (m, 1H), 3.42-3.34 (m, 2H), 3.16 (dd, J=10.2, 5.1, 1H), 3.03 (d, J=6.9, 2H), 2.34-2.18 (m, 1H), 1.91 (m, 2H), 0.99 (d, J=6.7, 6H).

Example 16 N-Cyclopentyl-4-piperazin-1-ylpyridin-2-amine

4-(2-Chloro-pyridin-4-yl)-piperazine-1-carboxylic acid tert-butyl ester. To a stirring solution of 2-chloro-4-bromopyridine (4.3 g, 2.5 mmol) in toluene (100 mL) was added piperazine-1-carboxylic acid tert-butyl ester (3.2 g, 17.2 mmol) and sodium tert-butoxide (2.5 g, 26.0 mmol). The flask was evacuated and flushed with N₂(g) twice. A mixture of Xantphos (600 mg, 1.0 mmol) and Pd₂(dba)₃ (318 mg, 0.35 mmol) was added in one portion and the mixture was heated at 85° C. for 20 h. The mixture was cooled to rt, diluted with H₂O (75 mL), and extracted with EtOAc (3×). The combined organic layers were dried and concentrated to give a clear golden oil. The oil was purified on FCC (0 to 5% 2 M NH₃ in MeOH/CH₂Cl₂) to give the title product as a beige solid (5.1 g, 100%). MS (ESI): mass calcd. for C₁₄H₂₀ClN₃O₂, 297.1; m/z found, 298.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 7.95 (d, J=5.9, 1H), 6.88-6.78 (m, 2H), 3.46-3.32 (m, 8H), 1.42 (s, 9H).

tert-Butyl 4-[2-(cyclopentylamino)pyridin-4-yl]piperazine-1-carboxylate. To a stirring solution of 4-(2-chloro-pyridin-4-yl)-piperazine-1-carboxylic acid tert-butyl ester (163 mg. 0.55 mmol) in toluene (2 mL) in a vial was added cyclopentylamine (136 μL, 1.38 mmol) and sodium tert-butoxide (161 mg, 1.68 mmol). A mixture of racemic BINAP (20 mg, 0.032 mmol) and Pd(OAc)₂ (18 mg, 0.027 mmol) was added in one portion and the mixture was heated at 85° C. for 20 h. The mixture was cooled to rt and purified directly by FCC (0 to 5% 2 M NH₃ in MeOH/CH₂Cl₂) to provide the title compound as a white solid (34 mg, 17%). MS (ESI): mass calcd. for C₁₉H₃₀N₄O₂, 346.2; m/z found, 347.3 [M+H]⁺. ¹H NMR (DMSO-d₆): 7.65 (d, J=6.0, 1H), 6.10 (d, J=6.0, 1H), 5.92 (d, J=7.1, 1H), 5.78 (s, 1H) 4.08-4.02 (m, 1H), 3.41 (t, J=5.4, 4H), 3.16 (t, J=5.4, 4H), 1.89-1.82 (m, 2H), 1.67-1.61 (m,2H), 1.59-1.48 (m, 2H), 1.42 (s, 9H), 1.43-1.35 (m, 2H).

N-Cyclopentyl-4-piperazin-1-ylpyridin-2-amine dihydrochloride. To a stirring solution of tert-butyl 4-[2-(cyclopentylamino)pyridin-4-yl]piperazine-1-carboxylate (34 mg, 0.1 mmol) in 96% formic acid (4 mL) was added 6 N aq HCl (2 drops). The mixture was stirred for 2 h and concentrated to give the desired product as a white solid (26 mg, 93%). MS (ESI): mass calcd. for C₁₄H₂₂N₄, 246.2; m/z found, 247.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 9.32 (s, 2H), 7.89 (d, J=7.1, 1H): 7.69 (d, J=7.5, 1H), 6.58 (d, J=7.6, 1H), 6.04 (s, 1H), 4.03-3.96 (m, 1H), 3.73 (t, J=4.9, 4H), 3.20 (t J=5.0, 4H), 2.03-1.95 (m, 2H), 1.73-1.68 (m, 2H), 1.64-1.52 (m, 2H), 1.50-1.42 (M, 2H).

The compounds in Example 17 through Example 20 were prepared using methods analogous to those described for Example 16.

Example 17 4-Piperazin-1-yl-N-propylpyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₂H₂₀N₄, 220.2; m/z found, 221.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 9.35 (br s, 2H), 7.87-7.82 (m, 1H), 7.69 (d, J=7.5, 1H), 6.57 (dd, J=7.5, 2.4, 1H), 6.05 (s, 1H), 3.79-3.69 (m, 4H), 3.32-3.13 (m, 6H), 1.63-1.51 (m, 2H), 0.94 (t, J=7.3, 3H).

Example 18 N-Benzyl-4-piperazin-1-ylpyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₆H₂₀N₄, 268.4; m/z found, 269.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.62 (d, J=7.5, 1H), 7.46-7.24 (m, 5H), 6.65 (dd, J=7.5, 2.1, 1H), 6.13 (d, J=2.0, 1H), 4.55 (s, 2H), 3.90-3.74 (m, 4H), 3.41-3.33 (m, 4H).

Example 19 N-(2-Methylpropyl)-4-piperazin-1-ylpyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₃H₂₂N₄, 234.4; m/z found, 235.3 [M+H]⁺. ¹H NMR (CDCl₃): 7.81 (d, J=6.1, 1H), 6.11 (dd, J=6.1, 2.3, 1H), 5.69 (d, J=2.0, 1H), 4.47 (s, 1H), 3.43-3.18 (m, 4H), 3.03 (t, J=6.2, 2H), 3.02-2.84 (m, 4H), 1.88 (pent, J=6.7, 1H), 0.99 (d, J=6.7, 6H).

Example 20 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine dihydrochloride

MS (ESI): mass calcd. for C₁₃H₂₂N₄, 234.4; m/z found, 235.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.54 (d, J=6.3, 1H), 5.97 (dd, J=6.4, 2.2, 1H), 5.53 (d, J=2.1, 1H), 3.67-3.60 (pent, J=5.5, 1H), 3.56-3.45 (m, 2H), 3.39-3.32 (m, 1H), 3.06 (dd, J=10.0, 4.9, 1H), 3.01 (d, J=6.9, 2H), 2.28-2.14 (m, 1H), 1.94-1.78 (m, 2H), 0.98 (d, J=6.7 Hz, 6H).

Example 21 4-(4-Methylpiperazin-1-yl)-N-(2-methylpropyl)pyridin-2-amine

Method A

(4-Iodo-pyridin-2-yl)-isobutyl-amine. A solution of 2-fluoro-4-iodopyridine (2.2 g, 1.0 mmol) in N-methylpyrrolidinone (10 mL) at rt was treated with isobutylamine (2.5 mL, 2.5 mmol) and the mixture was heated at 100° C. for 6 h. The mixture was cooled to rt, diluted with EtOAc (50 mL), and washed with water (2×10 mL). The combined aqueous extracts were back-extracted with EtOAc and the combined organic layers were dried and concentrated to yield a thick oil which solidified on standing (2.6 g, 95%). The solid was used without further purification. ¹H NMR (CDCl₃): 7.72 (d, J=5.3, 1H), 6.89 (dd, J=5.3, 1.4, 1H), 6.77 (d, J=1.1, 1H), 4.58 (s, 1H), 3.04 (dd, J=6.8, 5.9, 2H), 1.87 (dp, J=13.4, 6.7, 1H), 0.98 (d, J=6.7, 6H).

4-(4-Methylpiperazin-1-yl)-N-(2-methylpropyl)pyridin-2-amine. A suspension of (4-iodo-pyridin-2-yl)-isobutyl-amine (78 mg, 0.3 mmol), N-methyl piperazine (0.04 mL, 0.4 mmol) 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (X-phos) (5.4 mg, 4 mol %), Pd₂dba₃ (3.2 mg, 2 mol %) in THF (1 mL) was treated with lithium bis(trimethylsilyl)amide (1.0 M in THF; 0.8 mL, 0.8 mmol) and heated at 65° C. for 16 h. The resulting solution was cooled to rt and concentrated to minimum volume, then purified directly by FCC (0 to 10% 2 M NH₃ in MeOH/CH₂Cl₂) to yield the desired product (29 mg, 41%). MS (ESI): mass calcd. for C₁₄H₂₄N₄, 248.4; m/z found, 249.3 [M+H]⁺. ¹H NMR (CDCl₃): 7.79 (d, J=6.1, 1H), 6.12 (dd, J=6.2, 2.3, 1H), 5.69 (d, J=2.2, 1H), 4.62 (s, 1H), 3.54-3.23 (m, 4H), 3.03 (dd, J=6.7, 5.8, 2H), 2.59-2.22 (m, 7H), 1.39 (dp, J=13.4, 6.7, 1H), 1.19-0.78 (m, 8H).

Method B

4-bromo-N-isobutylpyridin-2-amine. A solution of 4-bromo-2-fluoropyridine (352 mg, 2 mmol) and 2-methylpropan-1-amine (584 mg, 8 mmol) in N-methyl-2-pyrrolidinone (NMP, 10 mL) was stirred at 100° C. for 1 hr. The reaction was allowed to cool to room temperature and diluted with DCM (50 mL), washed with water (10 mL*2). The organic layer was dried over Na₂SO₄, filtered and concentrated. The residue was purified by column chromatography (0-20% EtOAc-petrolumn ether gradient elation) to afford the desired product as oil (382 mg, 83%). ¹H NMR (300 MHz, CDCl₃): 7.86 (d, J=5.1 Hz, 1H), 6.98 (d, J=5.4 Hz, 1H), 6.53 (s, 1H), 4.75 (s, 1H), 3.03 (dd, J=6.6 Hz, 6.0 Hz, 2H), 1-88-1.86 (m, 1H), 0.98 (s, 3H), 0.96 (s, 3H); LC-MS: m/z=229.2, 231.2 [M+H]⁺.

N-isobutyl-4-(4-methylpiperazin-1-yl)pyridin-2-amine. A mixture of 4-bromo-N-isobutylpyridin-2-amine (153 mg, 0.7 mmol), 1-methylpiperazine (80 mg, 0.8 mmol), Pd₂(dba)₃ (6.1 mg, 0.007 mmol) and X-phos (12.7 mg, 0.028 mmol) in anhydrous THF (4 mL) was treated with LiHMDS (1.0M, 2.0 mL, 2 mmol) under atmosphere of nitrogen. The resulting reaction was stirred at 65° C. for 3 hrs and diluted with DCM (20 mL), washed with water (4 mL). The organic layer was dried over Na₂SO₄, filtered and concentrated. The residue was purified by column chromatography (0-10% MeOH-DCM gradient elation) to afford the desired product (60 mg, 34%). ¹H NMR (300 MHz, CDCl₃): 7.74 (d, J=6.6 Hz, 1H), 6.12 (d, J=6.3 Hz, 1H), 5.66 (s, 1H), 3.31 (t, J=5.4 Hz, 4H), 3.01 (d, J=6.0 Hz, 2H), 2.51 (t, J=5.4 Hz, 4H), 2.34 (s, 3H), 1.90-1.88 (m, 1H), 1.00 (s, 3H), 0.98 (s, 3H); LC-MS: m/z=249.1 [M+H]⁺.

N-isobutyl-4-(4-methylpiperazin-1-yl)pyridin-2-amine dihydrochloride. N-isobutyl-4-(4-methylpiperazin-2-yl)pyridin-2-amine (60 mg, 0.24 mmol) was dissolved in MeOH (1 mL) and aqueous HCl solution (6N, 0.5 mL) was added. The resulting reaction was stirred at 30° C. for 2 hrs. The reaction was concentrated under reduced pressure to afford the desired product (80 mg, 93%), 1H NMR (300 MHz, DMSO-d₆): 12.59 (s, 1H), 11.49 (brs, 1H), 7.97 (s, 1H), 7.72 (m, 1H), 6.60 (d, J=6.9 Hz, 1H); 6.12 (s, 1H), 4.20 (d, J=14 Hz, 2H), 4.00 (br s, 2H), 3.50-3.42 (m, 2H), 3.10 (m, 4H), 2.77 (s, 3H), 1.83-1.79 (m, 1H), 0.94 (d, J=6.6 Hz, 6H); LC-MS. m/z=249.2 [M+H]⁺, t_(R)=0.1 min; HPLC: 96% (214 nm), 96% (254 nm), t_(R)=4.5 min.

Example 22 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine

A solution of (4-iodo-pyridin-2-yl)-isobutyl-amine (96 mg, 0.4 mmol), (3R)-(methylamino)pyrrolidine (0.08 mL, 0.8 mmol), and Yb(OTf)₃ (215 mg, 0.4 mmol) in DMA (2 mL) was heated at 200° C. for 2 h in a microwave. The resulting solution was cooled to rt and concentrated to a minimum volume, then purified directly by FCC (0 to 10% 2 M NH₃ in MeOH/CH₂Cl₂). The material obtained (58 mg) was further purified by reversed-phase HPLC (Dionex conditions) to yield the title compound (10 mg, 11%). MS (ESI): mass calcd. for C₁₄H₂₄N₄, 248.4; m/z found, 249.3 [M+H]⁺. ¹H NMR (CDCl₃): 7.73 (d, J=5.0, 1H), 5.86 (dd, J=6.1, 2.0, 1H), 5.38 (d, J=2.0, 1H), 4.70-4.45 (m, 1H), 3.51 (dd, J=9.8, 6.2, 1H), 3.44 (dd, J=14.7, 8.7, 1H), 3.39-3.29 (m, 2H), 3.10 (dd, J=9.7, 4.9, 1H), 3.03-2.97 (m, 2H), 2.48 (s, 3H), 2.20 (dd, J=12.8, 7.6, 1H), 1.96-1.77 (m, 2H), 0.99 (d, J=6.7, 7H).

Example 23 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine.

[(3R)-1-(2-Chloro-pyrimidin-4-yl)-pyrrolidin-3-yl]-carbamic acid tert-butyl ester.

To a slurry of 2,4-chloropyrimidine (2.05 g, 13.7 mmol) and N,N-diisopropylethylamine (3.60 mL, 20.6 mmol) in i-PrOH (12 mL) was added (R)-3-N-Boc-amino pyrrolidine (2.69 g, 14.4 mmol). The mixture was heated at 160° C. in a microwave for 2 h. The reaction was cooled to rt and concentrated, and the crude residue was purified by FCC (0 to 50% EtOAc/hexanes) to yield a white solid (2.10 g, 51%). MS (ESI): mass calcd. for C₁₃H₁₉ClN₄O₂, 298.1; m/z found, 299.1 [M+H]⁺. ¹H NMR (CDCl₃): 8.02 (d, J=6.0, 1H), 6.19 (d, J=6.0, 1H), 4.85-4.47 (m, 1H), 4.40-4.18 (m, 1H), 3.94-3.08 (m, 4H), 2.46-2.17 (m, 1H), 2.12-1.78 (m, 1H), 1.45 (s, 9H).

[(3R)-1-(2-Isobutylamino-pyrimidin-4-yl)-pyrrolidin-3-yl]-carbamic acid tert-butyl ester. To a slurry of [(3R)-1-(2-chloro-pyrimidin-4-yl)-pyrrolidin-3-yl]-carbamic acid tert-butyl ester (103 mg, 0.35 mmol) and N,N-diisopropylethylamine (0.09 mL, 0.52 mmol) in i-PrOH (1.5 mL) was added isobutylamine (30 mg, 0.41 mmol). The mixture was heated to 140° C. in a microwave for 6 h. The reaction was cooled to room temperature and concentrated. The crude residue was purified by FCC (0 to 10% MeOH/CH₂Cl₂) to yield the desired product (93 mg, 80%). MS (ESI): mass calcd. for C₁₇H₂₉N₅O₂, 335.2; m/z found, 336.3 [M+H]⁺. ¹H NMR (CDCl₃): 7.83 (d, J=5.9, 1H), 5.64 (d, J=5.9, 1H), 4.98-4.80 (m, 1H), 4.78-4.61 (m, 1H), 4.38-4.20 (m, 1H), 3.79-3.26 (m, 4H), 3.23-3.11 (m, 2H), 2.32-2.09 (m, 1H), 1.99-1.77 (m, 2H), 1.45 (s, 9H), 0.95 (d, J=6.7, 6H).

4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine. To a solution of [(3R)-1-(2-isobutylamino-pyrimidin-4-yl)-pyrrolidin-3-yl]-carbamic acid tert-butyl ester (93 mg, 0.28 mmol) in MeOH (0.5 mL) was added HCl (4.0 M in 1,4-dioxane; 1.0 mL). The reaction was stirred at rt for 2 h, concentrated, and the crude residue was purified by FCC (0 to 20% 2 M NH₃ in MeOH/CH₂Cl₂) to yield the desired product (65 mg, 100%). MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.2; m/z found, 236.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.82 (d, J=5.9, 1H), 5.65 (d, J=5.9, 1H), 4.87 (s, 1H), 3.75-3.51 (m, 3H), 3.48-3.38 (m, 1H), 3.20 (dd, J=6.7, 6.1, 3H), 2.16 (d, J=6.3, 1H), 1.87 (dt, J=13.4, 6.7, 1H), 1.81-1.71 (m, 1H), 1.47 (s, 2H), 0.95 (d, J=6.7, 6H).

The compounds in Example 24 through Example 30 were prepared using methods analogous to those described for Example 23.

Example 24 4-[(3R)-3-Aminopyrrolidin-2-yl]-N-(cyclopropylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.2; m/z found, 234.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.83 (d, J=5.9, 1H), 5.66 (d, J=5.9, 1H), 4.89 (s, 1H), 3.76-3.37 (m, 4H), 3.23 (dd, J=7.0, 5.6, 2H). 3.20-3.11 (m, 1H), 2.21-2.10 (m, 1H), 1.82-1.70 (m, 1H), 1.40 (s, 2H), 1.16-0.97 (m, 1H), 0.59-0.39 (m, 2H), 0.32-0.14 (m, 2H).

Example 25 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.2; m/z found, 248.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.83 (d: J=5.9, 1H), 5.65 (d, J=5.9, 1H), 4.74 (d, J=6.6, 1H), 4.33-4.11 (m, 1H), 3.80-2.93 (m, 5H), 2.22-2.10 (m, 1H), 2.08-1.96 (m, 2H), 1.82-1.54 (m, 5H), 1.51-1.17 (m, 4H).

Example 26 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2,2-dimethylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.2; m/z found, 250.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.82 (d, J=5.9, 1H), 5.684 (d, J=5.9, 1H), 4.96-4.66 (m, 1H), 3.80-3.33 (m, 4H), 3.23 (d, J=6.4, 2H), 3.20-3.08 (m, 1H), 2.27-2.04 (m, J=6.2, 1H), 1.85-1.63 (m, 1H), 1.26 (s, 2H), 0.95 (s, 9H).

Example 27 1-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2-methylpropan-2-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.2; m/z found, 252.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.79 (d, J=6.0, 1H), 5.93 (br s, 1H), 5.69 (d, J=6.0, 1H), 6.23 (s, 1H), 3.77-3.30 (m, 6H), 3.28-2.93 (m, 1H), 2.24-2.05 (m, 1H), 1.88-1.71 (m, 1H), 1.66-1.33 (m, 2H), 1.23 (s, 6H).

Example 28 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclobutylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.2; m/z found, 234.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.82 (d, J=5.9, 1H), 5.65 (d, J=5.9, 1H), 5.00-4.83 (m, 1H), 4.51-4.35 (m, 1H), 3.76-3.32 (m, 4H), 3.25-2.96 (m, 1H), 2.47-2.30 (m, 2H), 2.23-2.06 (m, 1H), 1.94-1.60 (m, 5H), 1.57-1.31 (m, 2H).

Example 29 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(3R)-tetrahydrofuran-3-yl]pyrimidine-2-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅O, 249.2; m/z found, 250.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.83 (d, J=5.9, 1H), 5.69 (d, J=5.9, 1H), 4.98-4.84 (m, 1H), 4.61-4.47 (m, 1H), 4.05-3.88 (m, 2H), 3.88-3.77 (m, 1H), 3.73-3.32 (m, 5H), 3.26-3.02 (m, 1H), 2.35-2.22 (m, 1H), 2.20-2.10 (m, 1H), 1.92-1.69 (m, 2H), 1.54-1.16 (m, 2H).

Example 30 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(tetrahydro-2H-pyran-4-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅O, 263.2; m/z found, 264.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.83 (d, J=5.9, 1H), 5.68 (d, J=5.9, 1H), 4.71 (d, J=7.5, 1H), 4.09-3.84 (m, 3H), 3.75-3.34 (m, 6H), 3.26-2.99 (m, 1H), 2.24-2.09 (m, 1H), 2.03 (d, J=12.3, 2H), 1.86-1.69 (m, 1H), 1.80-1.19 (m, 4H).

Example 31 Isobutyl-[4-(4-methyl-piperazin-1-yl)-pyrimidin-2-yl]-amine

(4-Chloro-pyrimidin-2-yl)-isodolyl-amine and (2-Chloro-pyrimidin-4-yl)-isobutyl-amine. To a slurry of 2,4-dichloropyrimidine (1.48 g, 10.0 mmol) and N,N-diisopropylethylamine (2.60 mL, 15.0 mmol) in i-PrOH (8 mL) was added isobutylamine (0.77 g, 10.5 mmol). The mixture was heated at 160° C. in a microwave for 1 h. The mixture was cooled to rt and concentrated to provide a mixture of regioisomers. (4-Chloro-pyrimidin-2-yl)-isobutyl-amine. MS (ESI): mass calcd. for C₈H₁₂ClN₃, 185.1; m/z found, 186.1 [M+H]⁺. ¹H NMR (CDCl₃): 8.13 (s, 1H), 6.53 (d, J=5.2, 1H), 5.43 (s, 1H), 3.25 (dd, J=8.9, 6.0, 2H), 1.98-1.79 (m, 1H), 0.97 (d, J=6.7, 6H). (2-Chloro-pyrimidin-4-yl)-isobutyl-amine. MS (ESI): mass calcd. for C₈H₁₂ClN₃, 185.1; m/z found, 186.1 [M+H]⁺. ¹H NMR (CDCl₃): 8.19-7.75 (m, 1H), 6.69-6.18 (m, 2H), 3.40-2.98 (m, 2H), 1.98-1.83 (m, 1H), 0.96 (d, J=6.6, 6H). Isobutyl-[4-(4-methyl-piperazin-1-yl)-pyrimidin-2-yl]-amine. To a slurry of an unmeasured portion of the mixture from the previous step (60 mg, 0.32 mmol) in i-PrOH (2.0 mL) was added 1-methylpiperazine (80 mg, 0.80 mmol). The mixture was heated at 160° C. in a microwave for 1 h. The mixture was cooled to rt and concentrated, and the crude residue was purified by preparatory TLC (7% 2 M NH₃in MeOH/CH₂Cl₂) to yield the desired product (12 mg). MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.2; m/z found, 250.3 [M+H]⁺. ¹H NMR (CDCl₃): 7.87 (d, J=6.0, 1H), 5.85 (d, J=6.1, 1H), 4.87 (s, 1H), 3.70-3.51 (m, 4H), 3.19 (dd, J=6.7, 6.0, 2H), 2.52-2.38 (m, 4H), 2.33 (s, 3H), 1.92-1.79 (m, 1H), 0.96 (d, J=6.7, 6H).

Example 32 was prepared using methods analogous to Example 31.

Example 32 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.2; m/z found, 250.3 [M+H]⁺. ¹H NMR (CDCl₃): 7.82 (d, J=5.9, 1H), 5.65 (d, J=5.9, 1H), 4.86 (s, 1H), 3.79-3.26 (m, 4H), 3.24-3.15 (m, 3H), 2.48 (s, 3H), 2.23-2.09 (m, 1H), 1.93-1.74 (m, 3H), 0.95 (d, J=6.7, 6H).

The compounds in Example 33 through Example 42 were prepared using methods analogous to those described for Example 1 or Example 16.

Example 33 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-phenylpyridin-2-amine

MS (ESI): mass calcd. for C_H₂₁N₅, 247.2 m/z found, 248.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.94 (d, J=6.1, 1H), 5.83 (d, J=6.1, 1H), 3.67-3.58 (m, 4H), 3.57-3.50 (m, 4H), 2.50-2.41 (m, 4H), 2.33 (s, 3H), 2.00-1.84 (m, 4H).

Example 34 4-[3-(Methylamino)azetidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine

MS (ESI): mass calcd. for C_H₂₂N₄, 268.4 m/z found, 269.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.70 (d, J=6.1, 1H), 7.35-7.28 (m, 2H), 7.28-7.18 (m, 2H), 6.92 (tt, J=7.4, 1.3, 1H), 6.08 (dd, J=6.1, 2.2, 1H), 5.95 (d, J=2.1, 1H), 3.49 (dd, J=10.0, 6.4, 1H), 3.46-3.37 (m, 1H), 3.37-3.24 (m, 3H), 3.09 (dd, J=10.0, 5.2, 1H), 2.21 (dq, J=7.7, 5.9, 1H), 1.93-1.80 (m, 1H).

Example 35 N-(Cyclopropylmethyl)-4-piperazin-1-ylpyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₀N₄, 232.3 m/z found, 233.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.81 (d, J=6.1, 1H), 6.12 (dd, J=6.1, 2.3, 1H), 5.70 (d, J=2.2, 1H), 4.58 (s, 1H), 3.23 (dd, J=8.1, 4.1, 4H), 3.08 (dd, J=6.5, 4.4, 2H), 3.02-2.93 (m, 4H), 1.99 (s, 2H), 1.17-0.99 (m, 1H), 0.63-0.39 (m, 2H), 0.33-0.10 (m, 2H).

Example 36 N-Butyl-4-piperazin-1-ylpyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₂N₄, 234.3 m/z found, 235.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.61 (d, J=6.3, 1H), 6.20 (dd, J=6.4, 2.4, 1H), 5.84 (d, J=2.3, 1H), 3.26 (dd, J=6.1, 4.2, 4H), 3.20 (t, J=7.0, 2H), 2.91 (dd, J=6.2, 4.1, 4H), 1.64-1.52 (m, 2H), 1.43 (dq, J=14.2, 7.2, 2H), 0.96 (dd, J=9.7, 5.0, 3H).

Example 37 N-(2-Methoxyethyl)-4-piperazin-1-ylpyridin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₀N₄O, 236.3 m/z found, 237.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.63 (d, J=6.3, 1H), 6.23 (dd, J=6.3, 2.3, 1H), 5.91 (d, J=2.3, 1H), 3.55 (t, J=5.5, 2H), 3.40 (t, J=5.4, 2H), 3.37 (s, 3H), 3.28-3.24 (m, 4H), 2.91 (dd, J=6.1, 4.2, 4H).

Example 38 N-Phenyl-4-piperazin-1-ylpyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₈N₄, 254.3 m/z found, 255.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.89-12.43 (m, 1H), 10.17 (s, 1H), 9.70 (s, 2H), 7.81 (d, J=7.5 Hz, 1H), 7.45 (t, J=7.8 Hz, 2H), 7.31 (d, J=7.7 Hz, 2H), 7.24 (t, J=7.3, Hz, 1H), 6.75 (dd, J=7.4, 2.1 Hz, 1H), 6.35 (d, J=2.0 Hz, 1H), 3.75 (s, 4H), 3.20 (s, 4H).

Example 39 4-Piperazin-1-yl-N-(tetrahydrofuran-2-ylmethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₂N₄O, 262.4 m/z found, 263.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.82 (d, J=6.1, 1H), 6.13 (dd, J=6.1, 2.3, 1H), 5.76 (d, J=2.2, 1H), 4.65 (s, 1H), 4.09 (qd, J=7.0, 4.0, 1H), 3.88 (dt, J=8.2, 6.7, 1H), 3.77 (dd, J=14.4, 7.6, 1H), 3.52 (ddd, J=13.0, 6.5, 4.0, 1H), 3.26 (dd, J=7.2, 5.1, 1H), 3.22 (dd, J=6.1, 4.0, 4H), 2.97 (dd, J=6.1, 4.1, 4H), 2.61 (s, 1H), 2.06-1.96 (m, 1H), 1.96-1.85 (m, 2H), 1.79 (s, 2H), 1.72-1.60 (m, 1H).

Example 40 N-(4-Fluorobenzyl)-4-piperazin-1-ylpyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₁₉FN₄, 286.4 m/z found, 287.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.84 (d, J=6.1, 1H), 7.39-7.29 (m, 2H), 7.08-6.93 (m, 2H), 6.16 (dd, J=6.1, 2.3, 1H), 5.68 (d, J=2.2, 1H), 4.68 (s, 1H), 4.44 (d, J=5.6, 2H), 3.18 (dd, J=6.2, 4.1, 4H), 2.95 (dd, J=6.2, 4.1, 4H).

Example 41 N-(2,2-Dimethylpropyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₆N₄O, 262.4 m/z found, 263.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.30 (s, 1H), 9.39 (br s, 2H), 7.70-7.60 (m, 2H), 6.26 (dd, J=7.4, 2.2, 1H), 5.79 (s, 1H), 3.89 (s, 1H), 3.81-3.3.62 (m, 3H), 3.53 (br s, 1H), 3.08 (d, J=6.0, 2H), 2.61 (s, 3H), 2.43-2.21 (m, 2H), 0.96 (s, 9H).

Example 42 N-(2-Methoxyethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.4 m/z found, 251.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 12.13 (s, 1H), 9.53 (s, 1H), 9.41 (s, 1H), 7.70-7.60 (m, 2H), 6.29 (dd, J=7.4, 2.2, 1H), 5.75 (s, 1H), 3.89 (s, 1H), 3.85-3.62 (m, 4H), 3.50 (t, J=4.8, 2H), 3.44 (t, J=5.5, 2H), 3.29 (s, 3H), 2.60 (s, 3H), 2.45-2.33 (m, 2H).

The compounds in Example 43 through Example 83 were prepared using methods analogous to those described for Example 23.

Example 43 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[bicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.4 m/z found, 274.2 [M+H]. ¹H NMR (D₂O): 8.69-8.29 (m, 1H), 7.64 (s, 1H), 6.14 (s, 1H), 4.25-3.52 (m, 6H), 2.63-2.12 (m, 4H), 1.96-1.74 (m, 1H), 1.65-1.04 (m, 8H).

Example 44 N-[Bicyclo[2.2.1]hept-2-yl]-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₅N, 287.41 m/z found, 288.2 [M+H]. ¹H NMR (CDCl₃): 7.87 (d, J=6.0, 1H), 5.84 (d, J=6.1, 1H), 4.69 (d, J=6.5, 1H), 3.75-3.67 (m, 1H), 3.63-3.52 (m, 4H), 2.48-2.39 (m, 4H), 2.32 (s, 3H), 2.29-2.22 (m, 2H), 1.86-1.75 (m, 1H), 1.56-1.38 (m, 3H), 1.30-1.09 (m, 4H).

Example 45 N-(Cyclopropylmethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.4 m/z found, 248.2 [M+H]. ¹H NMR (D₂O): 7.88 (d, J=8.1, 1H), 5.86 (d, J=6.1, 1H), 4.93 (s, 1H), 3.65-3.55 (m, 4H), 3.22 (dd, J=7.0, 5.5, 2H), 2.47-2.41 (m, 4H), 2.32 (s, 3H), 1.11-0.99 (m, 1H), 0.53-0.46 (m, 2H), 0.25-0.18 (m, 2H).

Example 46 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-butylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.3 m/z found, 236.2 [M+H]. ¹H NMR (CDCl₃): 7.83 (d, J=5.9, 1H), 5.65 (d, J=5.9, 1H), 4.75 (s, 1H), 3.75-3.00 (m, 7H), 2.23-2.07 (m, 1H), 1.85-1.67 (m, 1H), 1.64-1.28 (m, 6H), 0.94 (t, J=7.3, 3H).

Example 47 N-Butyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.4 m/z found, 250.2 [M+H]. ¹H NMR (CDCl₃): 7.87 (d, J=6.0, 1H); 5.85 (d, J=6.1, 1H), 4.78 (s, 1H), 3.65-3.53 (m, 4H), 3.41-3.28 (m, 2H), 2.47-2.40 (m, 4H), 2.32 (s, 3H), 1.63-1.48 (m, 2H), 1.45-1.31 (m, 2H), 0.94 (t, J=7.3, 3H),

Example 48 N-Cyclopentyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.4 m/z found, 262.2 [M+H]. ¹H NMR (CDCl₃): 7.87 (d, J=6.1, 1H), 5.85 (d, J=6.1, 1H), 4.79 (d, J=6.6, 1H), 4.28-4.13 (m, 1H), 3.70-3.51 (m, 4H), 2.48-2.38 (m, 4H), 2.32 (s, 3H), 2.07-1.94 (m, 2H), 1.77-1.53 (m, 4H), 1.51-1.37 (m, 2H).

Example 49 N-(2,2-Dimethylpropyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.4 m/z found, 264.2 [M+H]. ¹H NMR (CDCl₃): 7.86 (d, J=6.0, 1H), 5.84 (d, J=6.1, 1H), 4.84 (s, 1H), 3.67-3.53 (m, 4H), 3.21 (d, J=6.3, 2H), 2.51-2.38 (m, 4H), 2.30 (s, 3H), 0.95 (s, 9H).

Example 50 4-(4-Methylpiperazin-1-yl)-N-(tetrahydrofuran-2-ylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅O, 277.4 m/z found, 278.2 [M+H]. ¹H NMR (CDCl₃): 7.87 (d, J=6.1, 1H), 5.86 (d, J=6.1, 1H), 5.07 (s, 1H), 4.11-4.01 (m, 1H), 3.92-3.84 (m, 1H), 3.79-3.71 (m, 1H), 3.63-3.51 (m, 5H), 3.47-3.36 (m, 1H), 2.47-2.39 (m, 4H), 2.32 (s, 3H), 2.03-1.83 (m, 3H), 1.69-1.58 (m, 1H).

Example 51 4-[(R)-3-Aminopyrrolidin-1-yl]-N-(tetrahydrofuran-2-ylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅O, 263.4 m/z found, 264.2 [M+H]. ¹H NMR (D₂O): 8.74-8.23 (m, 1H), 7.65 (d, J=7.2, 1H), 6.16 (s, 1H), 4.28-3.41 (m, 11H), 2.64-2.41 (m, 1H), 2.37-2.15 (m, 1H), 2.12-1.83 (m, 4H), 1.76-1.59 (m, 1H).

Example 52 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(1-methylethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅, 221.3 m/z found, 222.2 [M+H]. ¹H NMR (D₂O): 8.64-8.31 (m, 1H), 7.62 (d, J=7.3, 1H), 6.14 (d, J=6.3, 1H), 4.24-3.59 (m, 6H), 2.65-2.40 (m, 1H), 2.37-2.11 (m, 1H), 1.23 (d, J=6.5, 8H).

Example 63 N-(1-Methylethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.3 m/z found, 236.2 [M+H]. ¹H NMR (CDCl₃): 7.87 (d, J=6.1, 1H), 5.84 (d, J=6.1, 1H), 4.63 (d, J=7.4, 1H), 4.16-4.00 (m, 1H), 3.66-3.50 (m, 4H), 2.49-2.39 (m, 4H), 2.32 (s, 3H), 1.21 (d, J=6.5, 6H).

Example 54 N-Cyclobutyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.4 m/z found, 248.2 [M+H]. ¹H NMR (CDCl₃): 7.86 (d, J=6.1, 1H), 5.85 (d, J=6.1, 1H), 4.99 (d, J=7.0, 1H), 4.46-4.35 (m, 1H), 3.65-3.53 (m, 4H), 2.47-2.34 (m, 6H), 2.32 (s, 3H), 1.93-1.80 (m, 2H), 1.77-1.63 (m, 2H).

Example 55 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclopropylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₇N₅, 219.3 m/z found, 220.2 [M+H]. ¹H NMR (D₂O): 8.64-8.30 (m, 1H), 7.71 (d, J=7.3, 1H), 6.23 (d, J=7.3, 1H), 4.22-4.02 (m, 1H), 4.00-3.88 (m, 1H), 3.85-3.59 (m, 3H), 2.76-2.59 (m, 1H), 2.56-2.38 (m, 1H), 2.32-2.11 (m, 1H), 0.98-0.80 (m, 2H), 0.72-0.58 (m, 2H).

Example 56 N-Cyclopropyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.3 m/z found, 234.2 [M+H]. ¹H NMR (CDCl₃): 7.93 (d, J=6.1, 1H), 5.91 (d, J=6.1, 1H), 5.02 (s, 1H), 3.65-3.55 (m, 4H), 2.78-2.68 (m, 1H), 2.48-2.39 (m, 4H), 2.32 (s, 3H), 0.79-0.70 (m, 2H), 0.54-0.47 (m, 2H).

Example 57 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-fluorobenzyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₈FN₅, 287.3 m/z found, 288.2 [M+H]. ¹H NMR (D₂O): 8.65-8.24 (m, 1H), 7.65 (d, J=7.1, 1H), 7.48-7.30 (m, 2H), 7.19-7.01 (m, 2H), 6.14 (d, J=7.0, 1H), 4.58 (s, 2H), 4.22-4.02 (m, 1H), 3.97-3.58 (m, 4H), 2.62-2.36 (m, 1H), 2.31-2.11 (m, 1H).

Example 58 N-(4-Fluorobenzyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₀FN₅, 301.4 m/z found, 302.2 [M+H]. ¹H NMR (CDCl₃): 7.85 (d, J=6.1, 1H), 7.34-7.26 (m, 2H), 7.03-6.92 (m, 2H), 5.88 (d, J=6.1, 1H), 5.30 (s, 1H) 4.54 (d, J=5.9, 2H), 3.61-3.53 (m, 4H), 2.45-2.37 (m, 4H), 2.31 (s, 3H).

Example 59 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.3 m/z found, 238.2 [M+H]. ¹H NMR (CDCl₃): 7.83 (d, J=5.9, 1H), 5.67 (d, J=5.9, 1H), 5.06 (s, 1H), 3.79-3.39 (m, 8H), 3.37 (s, 3H), 3.24-3.00 (m, 1H), 2.26-2.05 (m, 1H), 1.84-1.69 (m, 1H), 1.65-1.21 (m, 2H).

Example 60 N-(2-Methoxyethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.3 m/z found, 252.2 [M+H]. ¹H NMR (CDCl₃): 7.88 (d, J=6.1, 1H), 5.87 (d, J=6.1, 1H), 5.09 (s, 1H), 3.65-3.50 (m, 8H), 3.37 (s, 3H), 2.48-2.39 (m, 4H), 2.32 (s, 3H).

Example 61 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-1-amine

MS (ESI): mass calcd. for C₁₄H₁₈N₆, 270.3 m/z found, 271.2 [M+H]. ¹H NMR (CDCl₃): 8.54 (d, J=4.2, 1H), 7.86 (d, J=5.9, 1H), 7.61 (td, J=7.7, 1.8, 1H), 7.34 (d, J=7.8, 1H), 7.16-7.10 (m, 1H), 5.72-5.61 (m, 2H), 4.73 (d, J=5.8, 2H), 3.71-3.32 (m, 4H), 3.21-3.04 (m, 1H), 2.20-2.05 (m, 1H), 1.80-1.68 (m, 1H), 1.38-1.13 (m, 2H).

Example 62 4-(4-Methylpiperazin-1-yl)-N-(pyridin-2-ylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₀N₆, 284.4 m/z found, 285.2 [M+H]. ¹H NMR (CDCl₃): 8.55 (ddd, J=4.8, 1.6, 0.8, 1H), 7.91 (d, J=6.1, 1H), 7.61 (td, J=7.7, 1.8, 1H), 7.33 (d, J=7.8, 1H), 7.17-7.11 (m, 1H), 5.89 (d, J=6.1, 1H), 5.72-5.66 (m, 1H), 4.71 (d, J=5.7, 2H), 3.61-3.53 (m, 4H), 2.43-2.37 (m, 4H), 2.31 (s, 3H).

Example 63 Cyclopentyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.3 m/z found, 248.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.89-7.84 (m, 1H), 5.87-5.83 (m, 1H), 4.26-4.18 (m, 1H), 3.62-3.52 (m, 4H), 2.95-2.87 (m, 4H), 2.07-1.98 (m, 2H), 1.77-1.67 (m, 2H), 1.66-1.58 (m, 2H), 1.61-1.41 (m, 2H).

Example 64 (2,2-Dimethyl-propyl)-(4-piperazin-1-yl-pyrimidin-2-yl)-amine

Method A:

The titled compound was prepared using methods analogous to those described for Example 23, MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.4 m/z found, 250.2 [+H]⁺. ¹H NMR (CDCl₃): 7.92-7.86 (m, 1H), 5.86-5.83 (m, 1H), 4.97-4.84 (m, 1H), 3.63-3.55 (m, 4H), 3.53-3.47 (m, 4H), 3.24-3.19 (m, 2H), 1.51-1.47 (m, 9H).

Method B:

t-butyl 4-(2-chloropyrimidin-4-yl)piperazine-1-carboxylate.

To a mixture of 2,4-dichloropyrimidine (20 g, 0.135 mol, 1 eq.) and DIPEA (26 g, 0.203 mol, 1.5 eq) in i-PrOH (400 mL) was added tert-butyl piperazine-1-carboxylate (27 g, 0.148 mol, 1.1 eq) by portions at 0° C., and the resulting reaction was stirred overnight (about 15 hrs) at 10° C. A lot of white solid precipitated and TLC showed that there was still a little 2,4-dichloropyrimidine. The solid was filtered and recrystallized from DCM to afford the title product (18 g, 45% yield) as a white solid. ¹H NMR (300 MHz, CDCl₃): 8.08 (d, J=6.2 Hz, 1H), 6.41 (d, J=6.2 Hz, 1H), 3.67 (s, 4H), 3.56-3.41 (m, 4H), 1.48 (s, 9H). t-butyl 4-(2-(neopentylamino)pyrimidin-4-yl)piperazine-1-carboxylate. A solution of tert-butyl 4-(2-chloropyrimidin-4-yl)piperazine-1-carboxylate (300 mg, 1 mmol) 2,2-dimethylpropan-1-amine (131 mg, 1.5 mmol) and DIPEA (259 mg, 2 mmol) in pentan-1-ol (15 mL) was stirred at reflux for 18 hrs. The solvent was removed under reduced pressure and the residue was purified by column chromatography (100% ethyl acetate) to afford the desired product. ¹H NMR (300 MHz, CDCl₃): 7.88 (d, J=5.7 Hz, 1H), 5.84 (d, J=6.3 Hz, 1H), 4.97 (br s, 1H), 3.58 (m, 4H), 3.50 (m, 4H), 3.21 (d, J=6.3 Hz, 2H), 1.48 (s, 9H), 0.98 (s, 9H).

N-neopentyl-4-(piperazin-1-yl)pyrimidin-2-amine dihydrochloride.

t-butyl 4-(2-(neopentylamino)pyrimidin-4-yl)piperazine-1-carboxylate obtained from the previous stey was dissolved in MeOH (4 mL) and 7N HCl/Et₂O solution (20 mL) was added. The resulting solution was stirred at ambient temperature for 18 hrs. The solvent was concentrated to give the desired product as a yellow solid (130 mg, 40% yield in two steps). ¹H NMR (300 MHz, CD₃OD): 7.84 (d, J=7.2 Hz, 1H), 6.56 (d, J=7.2 Hz, 1H), 4.27 (br s, 2H), 4.02 (br s, 2H), 3.40 (br s, 4H), 3.33 (br s, 2H), 1.01 (s, 9H); LC-MS, m/z=250.2 [M+H]⁺. t_(R)=0.8 min; HPLC: 99% (214 nm), 98% (254 nm), t_(R)=4.7 min.

Example 65 Isobutyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₆, 235.3 m/z found, 236.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.89-7.78 (m, 1H), 6.62-6.52 (m, 1H), 4.13-3.97 (m, 2H), 3.44-3.37 (m, 4H), 3.35-3.18 (m, 4H), 2.02-1.89 (m, 1H), 1.04-0.97 (m, 6H).

Example 88 Cyclopropylmethyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine

MS (ESI): mass calcd. for C₁₂H₂₁₉N₅, 233.3 m/z found, 234.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.87-7.78 (m, 1H), 6.64-6.53 (m, 1H), 3.46-3.36 (m, 4H), 3.35-3.29 (m, 4H), 1.20-1.07 (m, 1H), 0.65-0.53 (m, 2H), 0.37-0.28 (m, 2H).

Example 67 Isopropyl-(4-piperazin-1-yl-pyrimidin-2-yl)amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅, 221.3 m/z found, 222.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.83-7.77 (m, 1H), 6.59-6.50 (m, 1H), 4.36-3.98 (m, 4H), 3.46-3.29 (m, 4H), 1.44-1.36 (m, 1H), 1.31-1.24 (m, 6H).

Example 68 Butyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.3 m/z found, 236.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.87-7.79 (m, 1H), 6.65-6.53 (m, 1H), 4.38-3.99 (m, 4H), 3.55-3.29 (m, 6H), 1.73-1.60 (m, 2H), 1.50-1.40 (m, 2H), 1.03-0.96 (m, 3H).

Example 69 (R)-(4-Piperazin-1-yl-pyrimidin-2-yl)-(tetrahydro-furan-2-ylmethyl)-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅O, 283.3 m/z found, 264.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.86-7.79 (m, 1H), 5.86-5.82 (m, 1H), 5.21-5.09 (m, 1H), 4.11-4.01 (m, 1H), 3.91-3.80 (m, 1H), 3.78-3.70 (m, 1H), 3.59-3.49 (m, 4H), 3.41-3.34 (m, 1H), 2.91-2.84 (m, 4H), 2.45-2.11 (m, 2H), 2.03-1.81 (m, 4H), 1.68-1.58 (m, 1H).

Example 70 Bicyclo[2.2.1]hept-2-yl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.4 m/z found, 274.2 [M+H]⁺. ¹H (CDCl₃): 7.93-7.82 (m, 1H), 5.87-5.81 (m, 1H), 4.99-4.74 (m, 1H), 3.75-3.67 (m, 1H), 3.62-3.54 (m, 4H), 3.52-3.44 (m, 4H), 2.30-2.22 (m, 2H), 1.85-1.77 (m, 1H), 1.59-1.51 (m, 1H), 1.46-1.40 (m, 1.6H), 1.29-1.20 (m, 2.4H), 1.19-1.11 (m, 2H).

Example 71 (4-Piperazin-1-yl-pyrimidin-2-yl)-(2,6,6-trimethyl-bicyclo[3.1.1]hept-3-yl)-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.5 m/z found, 316.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.54-7.41 (m, 1H), 6.25-6.14 (m, 1H), 4.33-4.12 (m, 1H), 4.10-3.91 (m, 2H), 3.88-3.62 (m, 2H), 3.29-3.13 (m, 4H), 2.52-2.37 (m, 1H), 2.32-2.19 (m, 1H), 1.91-1.73 (m, 2H), 1.72-1.63 (m, 1H), 1.53-1.41 (m, 1H), 1.02 (s, 3H), 0.94-0.88 (m, 3H), 0.85 (s, 3H), 0.77-0.71 (m, 2H).

Example 72 N-(2-Methoxyethyl)-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.3 m/z found, 238.3 [M+H]⁺. ¹H NMR (CD₃OD): 7.84 (d, 1H, J=7.4), 6.59 (d, 1H, J=7.3), 4.29 (bs, 2H), 4.04 (bs, 2H), 3.59-3.67 (m, 4H), 3.35-3.45 (m, 7H).

Example 73 Butyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.2 m/z found, 250.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.82 (d, J=5.9, 1H), 5.64 (d, J=5.9, 1H), 4.90 (s, 1H), 3.77-3.08 (m, 7H), 2.46 (s, 3H), 2.14 (td, J=13.1, 6.1, 1H), 1.81 (d, J=6.1, 1H), 1.67-1.29 (m, 5H), 0.93 (t, J=7.3, 3H).

Example 74 Bicyclo[2.2.1]hept-2-yl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₆H₂₅N₅, 287.2 m/z found, 288.2 [M+H]. ¹H NMR (CDCl₃): 7.76 (d, J=5.8, 1H), 5.60 (d, J=5.9, 1H), 5.12-4.88 (m, 1H), 3.69 (S, 2H), 3.29 (s, 2H), 2.61-1.98 (m, 6H), 1.95-0.92 (m, 12H).

Example 75 Cyclopentyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.2 m/z found, 262.2 [M+H]. ¹H NMR (CDCl₃): 7.75 (d, J=5.9, 1H), 5.58 (d, J=5.9, 1H), 4.97 (s, 1H,), 4.17 (dd, J=13.6, 6.8, 1H), 3.53 (s, 1H), 3.25 (s, 3H), 2.40 (s, 3H), 2.18-1.28 (m, 12H).

Example 76 (2,2-Dimethyl-propyl)-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.2 m/z found, 264.2 [M+H]. ¹H NMR (CDCl₃): 7.77 (d, J=5.8, 1H), 5.59 (d, J=5.9, 1H), 4.92 (s, 1H), 3.56 (s, 1H), 3.22-3.15 (m, 5H), 2.43 (s, 3H), 2.11 (d, J=6.0, 1H), 1.78 (s, 1H), 1.08-0.73 (m, 11H).

Example 77 Cyclopropylmethyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.2 m/z found, 248.2 [M+H]. ¹H NMR (CDCl₃): 7.61 (d, J=5.9, 1H), 5.44 (d, J=5.9, 1H), 4.87 (s, 1H), 3.57-2.78 (m, 7H), 2.46-2.04 (m, 3H), 1.93 (td, J=13.3, 6.0, 1H), 1.60 (d, J=6.1, 1H), 1.32-0.60 (m, 2H), 0.38-0.16 (m, 2H), 0.14-0.10 (m, 2H).

Example 78 Isopropyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.2 m/z found, 236.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.81 (d, J=5.9, 1H), 5.64 (d, J=5.9, 1H), 4.82 (d, J=7.3, 1H), 4.21-4.00 (m, 1H), 3.77-3.08 (m, 5H), 2.67-2.25 (m, 3H), 2.24-1.71 (m, 2H), 1.67-0.90 (m, 7H).

Example 79 (4-Fluoro-benzyl)-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]amine

MS (ESI): mass calcd. for C₁₆H₂₀FN₅, 301.2 m/z found, 302.2 [M+H]. ¹H NMR (CDCl₃): 7.78 (d, J=5.7, 1H), 7.40-7.20 (m, 2H), 7.06-6.86 (m, 2H), 5.65 (d, J=5.9, 2H), 4.53 (d, J=5.9, 2H), 3.56-3.48 (m, 2H), 3.29 (s, 3H), 2.44 (s, 3H), 2.11 (s, 1H), 1.79 (s, 1H), 1.40-1.32 (m, 1H).

Example 80 Cyclopropyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.2 m/z found, 234.2 [M+H]. ¹H NMR (CDCl₃) 7.89 (d, J=5.9, 1H), 5.71 (d, J=6.0, 1H), 5.13 (s, 1H), 3.76-3.11 (m, 5H), 2.82-2.39 (m, 4H), 2.15 (td, J=13.2, 6.0, 1H), 1.82 (d, J=6.1, 1H), 1.46 (s, 1H), 0.85-0.64 (m, 2H), 0.60-0.40 (m, 2H).

Example 81 [4-(3R)-(3-Methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-(tetrahydro-furan-2-ylmethyl)-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅O, 277.2 m/z found, 278.2 [M+H]. ¹H NMR (CDCl₃): 7.82 (d, J=5.9, 1H), 5.66 (d, J=5.9, 1H), 5.11 (s, 1H), 4.15-3.99 (m, 1H), 3.96-3.12 (m, 9H), 2.55 (s, 3H), 2.34-2.05 (m, 1H), 2.05-1.56 (m, 6H).

Example 82 (2-Methoxy-ethyl)-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.2 m/z found, 252.2 [M+H]⁺. ¹H NMR (CDCl₃): 7.82 (d, J=5.9, 1H), 5.66 (d, J=5.9, 1H), 5.17 (s, 1H), 3.79-3.07 (m, 13H), 2.55 (s, 3H), 2.15 (td, J=13.3, 6.0, 1H), 1.82 (d, J=6.1, 1H).

Example 83 [4-(3R)-(3-Methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-pyridin-2-ylmethyl-amine

MS (ESI): mass calcd. for C₁₅H₂₀N₆, 284.2 m/z found, 285.2 [M+H]⁺. ¹H NMR (CDCl₃) 8.46 (d, J=4.8, 1H), 7.75 (d, J=5.9, 1H), 7.63-7.39 (m, 1H), 7.28 (d, J=7.8, 1H), 7.16-6.95 (m, 1H), 6.04 (s, 1H), 5.60 (d, J=5.9, 1H), 4.66 (d, J=5.8, 2H), 3.49 (s, 2H), 3.40-3.31 (m, 1H), 3.22 (s, 2H), 2.36 (s, 3H), 2.03 (s, 1H), 1.72 (s, 1H), 1.44-1.35 (m, 1H).

Example 84 [4-(3-Amino-azetidin-1-yl)-pyrimidin-2-yl]-butyl-amine

[1-(2-Chloro-pyrimidin-4-yl)-azetidin-3-yl]-carbamic acid tert-butyl ester To a flask containing 2,4-dichloropyrimidine (1.6 g, 10.7 mmol) and N,N-diisopropylethylamine (3.5 mL, 20.1 mmol) in i-PrOH (40 mL) was added azetidin-3-yl-carbamic acid tert-butyl ester monohydrochloride (2.1 g. 12.2 mmol). The reaction mixture was heated to 70° C. for 72 h. The reaction was cooled to room temperature, concentrated and the crude residue was purified by flash chromatography on SiO₂ (100% hexane increasing gradient to 60% EtOAc-Hexane) to yield two isomeric products. The minor upper R_(t) product was obtained as a white solid (326 mg, 11%), and the desired major lower R_(f) product was also obtained as a white solid (2.1 g, 69%).

[1-(2-Butylamino-pyrimidin-4-yl)-azetidin-3-yl]-carbamic acid tert-butyl ester. To a solution of [1-(2-chloro-pyrimidin-4-yl)-azetidin-3-yl]-carbamic acid tert-butyl ester (250 mg, 0.778 mmol) in i-PrOH (3.0 mL) was added butylamine (600 μL, 6.0 mmol). The reaction mixture was heated to 96° C. in a sealed tube for 36-48 h followed by cooling to room temperature. The reaction mixture was then concentrated and the crude residue purified by flash chromatography on SiO₂ using (100% EtOAc increasing the gradient gradually to 5% 2M NH₃—MeOH) to yield the desired product (260 mg, 92%).

[4-(3-Amino-azetidin-1-yl)-pyrimidin-2-yl]-butyl-amine. To a solution of [1-(2-butylamino-pyrimidin-4-yl)-azetidin-3-yl]-carbamic acid tert-butyl ester (250 mg, 0.778 mmol) in formic acid (4 mL) was added 6N HCl (300 μL). The reaction mixture was stirred at room temperature for 15-30 minutes. Then, MeOH (10 mL) was added and stirred for 10 minutes. The contents were then concentrated and the crude residue purified by flash chromatography on SiO₂ using an increasing gradient of (0 to 10% NH₃/MeOH in CH₂Cl₂) to yield the desired product (225 mg, 98%) as the free base. MS (ESI): mass calcd. for C₁₁H₁₉N₅, 221.3 m/z found, 222.2 [M+H]⁺. ¹H NMR (CD₃OD): 7.61 (d, J=7.3, 1H), 5.99 (d, J=7.1, 1H), 4.6-4.7 (m, 2H), 4.28-4.48 (m, 3H), 3.40 (bs, 1H), 1.54-1.62 (m, 2H), 1.31-1.41 (m, 2H), 0.90 (t, J=7.4, 3H).

The compounds in Example 85 through Example 94 were prepared using methods analogous to those described for Example 84.

Example 85 4-(3-Aminoazetidin-1-yl)-N-cyclopentylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.3 m/z found, 234.2 [M+H]. ¹H NMR (CDCl₃): 7.84 (d, J=6.0, 1H), 5.54 (d, J=5.8, 1H), 4.47 (bs, 1H), 4.20-4.28 (m, 3H), 3.90-3.98 (m, 1H), 3.60-3.65 (m, 2H), 1.97-2.06 (m, 2H), 1.55-1.75 (m, 6H), 1.39-1.48 (m, 2H).

Example 86 4-(3-Aminoazetidin-1-yl)-N-(cyclopropylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₇N₅, 219.3 m/z found, 220.2 [M+H]. ¹H NMR (CDCl₃): 7.62 (d, J=7.3, 1H), 6.00 (d, J=7.3, 1H), 4.6-4.7 (m, 2H), 4.28-4.40 (m, 3H), 3.24 (d, J=6.9, 2H), 1.05-1.15 (m, 1H), 0.52-0.59 (m, 2H), 0.23-0.30 (m, 2H).

Example 37 4-(3-Aminoazetidin-1-yl)-N-bicyclo[2.2.1]hept-2-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₁N₅, 259.4 m/z found, 260.2 [M+H]. ¹H NMR (CDCl₃): 7.60 (d, J=7.2, 1H), 6.00 (d, J=6.8, 1H), 4.55-4.70 (m, 2H), 4.25-4.43 (m, 3H), 3.65 (bs, 1H), 2.25-2.35 (m, 2H), 1.80-1.84 (m, 1H), 1.32-1.60 (m, 4H), 1.10-1.30 (m, 3H).

Example 88 4-(3-Aminoazetidin-1-yl)-N-(2,2-dimethylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.3 m/z found, 236.2 [M+H]. ¹NMR (CDCl₃): 7.61 (d, J=7.2, 1H), 5.99 (d, J=7.1, 1H), 4.58-4.70 (m, 2H), 4.28-4.42 (m, 2H), 3.22 (bs, 1H), 0.934 (s, 9H).

Example 89 4-(3-Aminoazetidin-1-yl)-N-(2-methylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅, 221.3 m/z found, 222.2 [M+H]. ¹H NMR (CDCl₃): 7.61 (d, J=7.8, 1H), 6.00 (d, J=7.0, 1H), 4.59-4.70 (m, 2H), 4.29-4.45 (m, 3H), 3.20 (bs, 2H), 1.85-1.94 (m, 1H), 0.92 (d, J=6.7, 6H).

Example 90 4-(3-Aminoazetidin-1-yl)-N-(1-methylethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₀H₁₇N₅, 207.3 m/z found, 208.2 [M+H]. ¹H NMR (CDCl₃): 7.83 (d, J=5.8, 1H), 5.54 (d, J=5.2, 1H), 4.7 (bs, 1H), 4.24 (apparent t, J=7.6 and 8.4, 2H), 4.05-4.15 (m, 1H), 3.90-3.98 (m, 1H), 3.60-3.85 (m, 2H), 1.75 (bs, 2H), 1.19 (d, J=6.4, 6H).

Example 91 4-(3-Aminoazetidin-1-yl)-N-cyclopropylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₀H₁₅N₅, 205.3 m/z found, 206.2. [M+H]. ¹H NMR (CDCl₃): 7.69 (d, J=7.3, 1H), 6.01 (d, J=7.3, 1H), 4.55-4.70 (m, 5H), 4.25-4.42 (m, 3H), 2.65 (bs, 1H), 0.85-0.95 (m, 2H), 0.66-0.71 (m, 2H).

Example 92 4-(3-Aminoazetidin-1-yl)-N-(4-fluorobenzyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₁₆FN₅, 273.3 m/z found, 274.2 [M+H]. ¹H NMR (CDCl₃): 7.62 (d, J=7.3, 1H), 7.39 (dd, J=5.7, 8.2, 2H), 7.12 (t, J=8.9, 2H), 6.00 (d, J=7.3, 1H), 4.52-4.65 (m, 4H), 4.23-4.40 (m, 3H).

Example 93 4-(3-Aminoazetidin-1-yl)-N-[(3R)-tetrahydrofuran-3-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₇N₅O, 235.3 m/z found, 236.2 [M+H]. ¹H NMR (CDCl₃): 7.64 (d, J=7.3, 1H), 6.04 (d, J=7.3, 1H), 4.55-4.68 (m, 3H), 4.30-4.41 (m, 3H), 3.94-4.10 (m, 2H), 3.85-3.91 (m, 1H), 3.79 (apparent dd, J=3.0, 9.8, 1H), 2.30-2.40 (m, 1H), 1.96-2.40 (m, 1H).

Example 94 4-(3-Aminoazetidin-1-yl)-N-[(2R)-tetrahydrofuran-2-ylmethyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅O, 249.3 m/z found, 250.2 [M+H]. ¹H NMR (D₂O): 7.63 (d, J=7.31, 1H), 6.02 (d, J=7.29, 1H), 4.58-4.68 (m, 2H), 4.30-4.41 (m, 3H), 4.12-4.20 (m, 1H), 3.75-3.90 (m, 2H), 3.48-3.55 (bs, 2H), 1.87-2.10 (m, 3H), 1.16-1.171 (m, 1H).

Example 95 5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyridazin-3-amine

[1-(6-Chloro-pyridazin-4-yl)-pyrrolidin-3-yl]-methyl-carbamic acid tert-butyl ester. A solution of 3,5-dichloropyridazine (149 mg, 1.0 mmol) in THF (3 mL) at 23° C. was treated with (R)-methyl-pyrrolidin-3-yl-carbamic acid tert-butyl ester (440 mg, 2.2 mmol) and the reaction stirred at 23° C. for 18 h. The reaction diluted with EtOAc (30 ml) and solution washed with water (2×5 ml) and combined organic solution dried and concentrated and crude material purified on 16 g SiO₂ (0 to 30% EtOAc:Hex) to yield 283 mg (91% yield) of the desired regioisomer and 17 mg (5% yield) of the undesired regioisomer. MS (ESI): mass calcd. for C₁₄H₂₁ClN₄O₂, 312.5 m/z found, 313.5 [M+H]⁺. [1-(6-Isobutylamino-pyridazin-4-yl)-pyrrolidin-3-yl]-methyl-carbamic acid tert-butyl ester. A solution of [1-(6-chloro-pyridazin-4-yl)-pyrrolidin-3-yl]-methyl-carbamic acid tert-butyl ester (32 mg, 0.1 mmol) in isobutylamine (1.0 ml) in a sealed tube was heated to 120° C. for 72 h. The resulting solution was purified directly on 12 g SiO₂ (0 to 5% NH₃/MeOH:CH₂Cl₂) to yield 20 mg (55% yield).

Isobutyl-[5-(3-methylamino-pyrrolidin-1-yl)-pyridazin-3-]-amine dihydrochloride. To a stirring solution of [1-(6-isobutylamino-pyridazin-4-yl)-pyrrolidin-3-yl]methyl-carbamic acid tert-butyl ester (19 mg, 0.08 mmol) in 96% formic acid (0.5 mL) was added 0.05 ml of aqueous 6N HCl. The mixture was stirred for 2 hr, diluted with MeOH and concentrated under reduced pressure (repeat 3×) to give the desired product as a white solid (101 mg, >99%). MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.4 m/z found, 250.2 [M+H]. ¹H NMR (400 MHz, CD₃OD): 8.12 (d, J=2.5, 1H), 6.08 (s, 1H), 4.11-4.01 (m, 1H), 4.04-3.47 (m, 4H), 3.35 (s, 1H), 3.15 (d, J=7.0, 2H), 2.82 (s, 3H), 2.85-2.53 (m, 1H), 2.43-2.31 (m, J=5.6, 1H), 1.96 (dt, J=13.4, 6.7, 1H), 1.03 (d, J=6.7, 6H). The compounds in Example 96 through Example 100 were prepared using methods analogous to those described for Example 95.

Example 96 N-Bicyclo[2.2.1]hept-2-yl-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₅N₅, 287.4 m/z found, 288.2 [M+H]⁺. ¹H NMR (CDCl₃): 8.07 (d, J=2.5, 1H), 5.44 (d, J=2.2, 1H), 4.60 (s, 1H), 3.51 (dd, J=15.3, 9.3, 2H), 3.40 (dd, J=12.2, 6.6, 3H), 3.14 (dd, J=9.9, 4.5, 1H), 2.49 (s, 3H), 2.29 (d, J=12.1, 2H), 2.21 (dd, J=14.0, 6.4, 1H), 1.95-1.79 (m, 2H), 1.49 (dd, J=20.4, 3.0, 4H), 1.33-1.10 (m, 5H).

Example 97 5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₉H₃₁N₅, 329.5 m/z found, 330.3 [M+H]⁺. ¹H NMR (CDCl₃): 8.07 (d, J=2.4, 1H), 5.49 (d, J=2.4, 1H), 4.58 (s, 1H), 3.93 (s, 1H), 3.58-3.44 (m, 3H), 3.44-3.29 (m, 3H), 3.14 (dd, J=9.8, 4.6, 1H), 2.67 (s, 1H), 2.49 (s, 3H), 2.40 (s, 1H), 2.21 (dd, J=13.4, 7.0, 1H), 1.98 (s, 1H), 1.88 (t, J=13.2, 3H), 1.65 (d, J=14.0, 2H), 1.50-1.43 (m, 2H), 1.24 (s, 3H), 1.17 (d, J=7.1, 3H), 1.07 (s, 3H), 0.98 (d, J=9.8, 1H).

Example 98 N-Cyclohexyl-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.2 [M+H]⁺. ¹H NMR (D₂O): 7.99 (d, J=2.3, 1H), 5.90 (s, 1H), 4.08 (s, 1H), 3.76 (s, 4H), 3.52 (s, 1H), 2.81 (s, 3H), 2.64-2.49 (m, 1H), 2.34 (d, J=5.8, 1H), 1.98 (s, 2H), 1.74 (s, 2H), 1.60 (s, 1H), 1.45-1.13 (m, 5H).

Example 99 N-(Cyclopropylmethyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.4 m/z found, 248.2 [M+H]⁺. ¹H NMR (CDCl₃): 8.09 (d, J=2.5, 1H), 5.47 (d, J=2.5, 1H), 4.70 (s, 1H), 3.56-3.44 (m, 2H), 3.43-3.29 (m, 2H), 3.13 (dd, J=7.0, 5.4, 3H), 2.48 (s, 3H), 2.25-2.12 (m, 1H), 1.89 (td, J=13.1, 5.8, 1H), 1.15-1.00 (m, 1H), 0.59-0.49 (m, 2H), 0.28-0.22 (m, 2H).

Example 100 N-Butyl-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.4 m/z found, 250.2 [M+H]⁺. ¹H NMR (D₂O): 8.01 (s, 1H), 5.93 (s, 1H), 4.09 (s, 1H), 3.74 (s, 4H), 3.31 (dd, J=13.2, 6.2, 2H), 2.81 (s, 3H), 2.59 (d, J=6.8, 1H), 2.35 (s, 1H), 1.69-1.55 (m, 2H), 1.39 (dd, J=14.9, 7.4, 2H), 0.91 (t, J=7.4, 3H).

Example 101 5-(4-Methylpiperazin-1-yl)-N-(2-methylpropyl)pyridazin-3-amine

3-Chloro-5-(4-methyl-piperazin-1-yl)-pyridazine. A solution of 3,5-dichloropyridazine (298 mg, 2.0 mmol) in THF (6 mL) at 23° C. was treated with N-methyl piperazine (490 μL, 2.2 mmol) and the reaction stirred at 23° C. for 18 h. The reaction diluted with EtOAc (30 ml) and solution washed with water (2×5 ml), and the aqueous back extracted with chloroform and combined organic solution dried and concentrated and crude material purified on 12 g SiO₂ (0 to 5% NH₃/MeOH:CH₂Cl₂) to yield 267 mg (60% yield) of the desired regioisomer. MS (ESI): mass calcd. for C₉H₁₃ClN₄, 212.5 m/z found, 213.3 [M+H]⁺.

5-(4-Methylpiperazin-1-yl)-N-(2-methylpropyl)pyridazin-3-amine. A solution of 3-chloro-5-(4-methyl-piperazin-1-yl)-pyridazine (103 mg, 0.5 mmol) in DME was treated with isobutylamine (145 μL, 1.5 mmol), Pd(OAc)₂ (23 mg, 0.03 mmol), and BINAP (22 mg, 0.04 mmol) in a sealed tube and heated to 85° C. for 1 h. The reaction was diluted with chloroform (15 ml), washed with water (5 ml) and the combined organics dried and concentrated and purified directly on 12 g SiO₂ (0 to 5% NH₃/MeOH:CH₂Cl₂) to yield 34 mg (28% yield). The HCl salt was prepared by dissolving the product in chloroform and adding 1.0 N HCl (0.3 mL, 0.3 mmol) in diethyl ether, and concentrating. MS (ESI): mass calcd. for C₉H₂₀N₆, 249.4 m/z found, 250.2 [M+H]⁺. ¹H NMR (DMSO-d₆): 14.04-13.83 (m, 1H), 11.61-11.35 (m, 1H), 8.46 (s, 2H), 8.33 (s, 1H), 8.51 (s, 1H), 4.38-4.16 (m, 2H), 3.64-3.48 (m, 4H), 3.22-3.06 (m, 4H), 2.86-2.73 (m, 3H), 1.91-1.78 (m, 1H), 0.95 (d, J=8.8, 6H).

The compounds in Example 102 through Example 206 were prepared using methods analogous to those described in Example 64, Method B.

Example 102 N-(Cyclohexylmethyl)-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.74 (d, J=7.2 Hz, 1H), 6.10 (d, J=6.9 Hz, 1H), 4.67-4.57 (m, 2H), 4.42-4.28 (m, 3H), 2.79 (s, 3H), 1.80-1.63 (m, 6H), 1.39-1.26 (m, 4H), 1.07-1.00 (m, 2H).

Example 103 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1R)-1-cyclohexylethyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₇N₅, 289.43 m/z found, 290.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.2 Hz, 1H), 6.26 (t, J=7.2 Hz, 1H), 4.15-3.68 (m, 6H), 2.60-2.48 (m, 1H), 2.32-2.21 (m, 1H), 1.90-1.70 (m, 5H), 1.60-1.40 (m, 1H), 1.40-1.30 (m, 3H), 1.25 (d, J=6.6 Hz, 3H), 1.20-1.00 (m, 2H).

Example 104 N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2

MS (ESI): mass calcd. for C₂₀H₃₁N₅, 341.5 m/z found, 342.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.5 Hz, 1H), 6.27 (d, J=7.2 Hz, 1H), 4.60-3.92 (m, 5H), 3.74-3.44 (m, 5H), 2.45-2.32 (m, 3H), 2.20-2.00 (m, 6H), 1.97-1.80 (m, 1H), 1.32 (s, 3H), 1.13 (s, 3H), 1.00-0.93 (m, 1H).

Example 105 N-[(6,6-Dimethylbicyclo[3.1.1]hept-2-yl)methyl]-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.74 (d, J=7.2 Hz, 1H), 6.10 (d, J=7.2 Hz, 1H), 4.75-4.57 (m, 2H), 4.42-4.28 (m, 3H), 3.55-3.45 (m, 2H), 2.79 (s, 3H), 2.44-2.36 (m, 2H), 2.04-1.96 (m, 5H), 1.60-1.57 (m, 1H), 1.25 (s, 3H), 1.12 (s, 3H), 0.99-0.95 (m, 1H).

Example 106 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(6,6-dimethylbicyclo[3.1.1]hept-2-yl)methyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.5 Hz, 1H), 6.28-6.23 (m, 1H), 4.14-3.87 (m, 5H), 3.55-3.45 (m, 2H), 2.59-2.41 (m, 3H), 2.30-2.20 (m, 1H), 2.03-1.88 (m, 5H), 1.63-1.58 (m, 1H), 1.25 (s, 3H), 1.12 (s, 3H), 0.98-0.88 (m, 1H).

Example 107 N-(Cyclohexylmethyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₇N₅, 301.44 m/z found, 302.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.28 (d, J=6.6 Hz, 1H), 4.52-3.93 (m, 4H), 3.77-3.38 (m, 6H), 2.44-2.37 m, 1H), 2.20-2.00 (m, 1H), 1.90-1.60 (m, 6H), 1.35-1.03 (m, 5H).

Example 108 4-[3-(Methylamino)azetidin-1-yl]-N-(tetrahydro-2H-pyran-4-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅O, 263.35 m/z found, 264.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.2 Hz, 1H), 6.13 (d, J=7.2 Hz, 1H), 4.70-4.60 (m, 2H), 4.50-4.28 (m, 3H), 4.20-3.96 (m, 3H), 3.56-3.52 (m, 2H), 2.78 (s, 3H), 2.00-1.90 (m, 2H), 1.66-1.61 (m, 2H).

Example 109 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(cyclopropylmethyl)pyrimidin-1-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.2 Hz, 1H), 6.29-6.25 (m, 1H), 4.15-3.70 (m, 5H), 2.59-2.46 (m, 1H), 2.32-2.21 (m, 1H), 1.20-1.16 (m, 1H), 0.59 (d, J=7.5 Hz, 2H), 0.33 (d, J=4.8 Hz, 2H).

Example 110 1-({4-[(3S)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2-methylpropan-2-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.79 (d, J=7.2 Hz, 1H), 6.29-6.25 (m, 1H), 4.07-3.67 (m, 5H), 3.49-3.48 (m, 2H), 2.59-2.46 (m, 1H), 2.30-2.17 (m, 1H), 1.26 (s, 6H).

Example 111 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2,2-dimethylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.36 m/z found, 250.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.78 (d, J=7.5 Hz, 1H), 6.28-6.24 (m, 1H), 4.49-3.67 (m, 5H). 2.61-2.47 (m, 1H), 2.30-2.18 (m, 1H), 1.00 (s, 9H).

Example 112 N-Cyclopropyl-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₇N₅, 219.29 m/z found, 220.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.5 Hz, 1H), 6.53 (d, J=7.5 Hz, 1H), 4.13 (br s, 2H), 3.90 (br s, 2H), 3.27 (br s, 4H), 2.56 (br s, 1H), 1.00-0.70 (m, 2H), 0.58 (br s, 2H).

Example 113 N-[(1R)-1-Cyclohexylethyl]-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₇N₅, 289.43 m/z found, 290.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.73 (d, J=7.2 Hz, 1H), 6.09 (d, J=7.2 Hz, 1H), 4.67-4.55 (m, 2H), 4.43-4.25 (m, 3H), 4.10-4.00 (m, 1H), 2.78 (s, 3H), 1.80-1.68 (m, 5R), 1.60-1.04 (m, 6H), 1.21 (d, J=8.6 Hz, 3H).

Example 114 2-Methyl-1-({4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-2-ol

MS (ESI): mass calcd. for C₁₃H₂₃N₅O, 265.36 m/z found, 266.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.80 (d, J=7.5 Hz, 1H), 6.28 (d, J=7.2 Hz, 1H), 4.06-3.50 (m, 7H), 2.84 (s, 3H), 2.60-2.55 (m, 1H), 2.50-2.30 (m, 1H), 1.28 (s, 6H).

Example 115 N-[(1R)-1-Cyclohexylethyl]-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.5 Hz, 1H), 6.28 (d, J=7.2 Hz, 1H), 4.60-4.40 (m, 2H), 4.20-3.90 (m, 3H), 3.73-3.58 (m, 1H), 3.70-3.60 (m, 3H), 2.45-2.33 (m, 1H), 2.20-2.00 (m, 1H), 1.90-1.70 (m, 5H), 1.60-1.40 (m, 1H), 1.40-1.30 (m, 3H), 1.25 (d, J=6.6 Hz, 3H), 1.20-1.00 (m, 2H).

Example 116 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.28 (br s, 1H), 4.62-4.41 (m, 1H), 4.18-3.64 (m, 5H), 2.78-2.41 (m, 3H), 2.32-1.75 (m, 5H), 1.21 (s, 3H), 1.21-1.08 (m, 7H).

Example 117 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-phenylethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.74 (d, J=7.2 Hz, 1H), 7.32-7.23 (m, 5H), 6.28-6.26 (m, 1H), 4.10-3.71 (m, 7H), 2.97 (t, J=7.2 Hz, 2H), 2.41-2.18 (m, 2H).

Example 118 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₁₈N₅, 270.34 m/z found, 271.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.88-8.86 (m, 1H), 8.65-8.63 (m, 1H), 8.20 (d, J=7.3 Hz, 1H), 8.05 (t, J=6.6 Hz, 1H), 7.91 (d, J=7.2 HZ, 1H), 6.41-6.38 (m, 1H), 5.11 (s, 2H), 4.12-3.98 (m, 1H), 3.84-3.35 (m, 4H), 2.61-2.38 (m, 1H), 2.29-2.08 (m, 1H).

Example 119 N-(Cyclopentylmethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.83 (d, J=6.0 Hz, 1H), 6.59 (br s, 1H), 5.15 (m, 1H), 4.42 (m, 1H), 3.71-3.27 (m, 8H), 2.99 (s, 3H), 2.22 (m, 1H), 1.90-1.60 (m, 6H), 1.31 (m, 2H).

Example 120 2-Methyl-2-{[4-(4-methylpiperazin-1-yl)pyrimidin-2-yl]amino}propan-2-ol

MS (ESI): mass calcd. for C₁₃H₂₃N₅O, 265.36 m/z found, 266.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.87 (d, J=7.2 Hz, 1H), 6.59 (d, J=7.2 Hz, 1H), 5.19 (m, 1H), 4.45 (m, 1H), 3.75-3.26 (m, 8H), 2.99 (s, 3H), 1.28 (s, 6H).

Example 121 N-(Cyclopentylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.74 (d, J=7.5 Hz, 1H), 6.24 (m, 1H), 4.03-3.37 (m, 7H), 2.59 (s, 3H), 2.70-2.50 (m, 1H), 2.30-2.22 (m, 2H), 1.83-1.64 (m, 6H), 1.34-1.30 (m, 2H).

Example 122 2-Methyl-1-({4-[3-(methylamino)azetidin-2-yl]pyrimidin-2-yl}amino)propan-2-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.78 (d, J=7.2 Hz, 1H), 6.13 (d, J=6.9 Hz, 1H), 4.69-4.58 (m, 2H), 4.45-4.30 (m, 3H), 3.55-3.48 (m, 2H), 2.80 (s, 3H), 1.22 (s, 6H).

Example 123 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.2 Hz, 1H), 6.29-6.26 (m, 1H), 4.08-3.50 (m, 7H), 2.60-2.40 (m, 1H), 2.40-2.20 (m, 2H), 1.83-1.65 (m, 6H), 1.34-1.32 (m, 2H).

Example 124 N-[2-(Methylsulfanyl)ethyl]-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅S, 253.37 m/z found, 254.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.73 (d, J=7.8 Hz, 1H), 6.47 (d, J=7.8 Hz, 1H), 4.16 (br s, 2H), 3.92 (br s, 2H), 3.58 (m, 2H), 3.31-3.28 (m, 4H), 2.66 (t, J=6.6 Hz, 2H), 2.05 (s, 3H).

Example 125 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₁N₅, 341.5 m/z found, 342.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.71 (d, J=7.2 Hz, 1H), 6.18 (d, J=7.5 Hz, 1H), 4.50-4.30 (m, 2H), 4.10-3.80 (m, 3H), 3.70-3.40 (m, 4H), 2.37-2.27 (m, 2H), 2.10-1.20 (m, 7H), 0.98 (s, 3H), 0.90 (s, 3H), 0.85 (s, 3H).

Example 128 4-[3-(Methylamino)azetidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.11 (d, J=7.2 Hz, 1H), 4.73-4.56 (m, 2H), 4.44-4.29 (m, 3H), 2.80 (s, 3H), 2.50-2.40 (m, 1H), 2.00-1.30 (m, 6H), 1.04 (s, 3H), 0.97 (s, 3H), 0.91 (s, 3H).

Example 127 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.78 (d, J=7.5 Hz, 1H), 6.28-6.24 (m, 1H), 4.60-4.40 (m, 1H), 4.16-3.73 (m, 5H), 2.60-2.26 (m, 3H), 1.90-1.74 (m, 3H), 1.53-1.30 (m, 3H), 1.13 (s, 3H), 1.00 (s, 3H), 0.92 (s, 3H).

Example 128 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.30-6.25 (m, 1H), 4.15-3.73 (m, 5H), 3.70-3.59 (m, 4H), 3.39 (s, 3H), 2.59-2.48 (m, 1H), 2.31-2.20 (m, 1H).

Example 129 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-cyclohexylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.5 Hz, 1H), 6.25 (t, J=6.9 Hz, 1H), 4.07-3.68 (m, 6H), 2.59-2.49 (m, 1H), 2.31-2.20 (m, 1H), 2.03-2.00 (m, 2H), 1.83-1.81 (m, 2H), 1.50-1.31 (m, 6H).

Example 130 3-({4-[(3S)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2,2-dimethylpropan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₃N₅O, 265.36 m/z found, 266.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=7.5 Hz, 1H), 6.21 (d, J=7.2 Hz, 1H), 4.08-3.61 (m, 5H), 3.50-3.26 (m, 4H), 2.53-2.41 (m, 1H), 2.24-2.14 (m, 1H), 0.91 (s, 6H).

Example 131 N-Benzyl-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.57 (br s, 1H), 9.44 (br s, 2H), 8.74 (br s, 1H), 7.93 (d, J=7.2 Hz, 1H), 7.34-7.24 (m, 5H), 6.52 (d, J=7.5 Hz, 1H), 4.54 (d, J=5.7 Hz, 2H), 3.95 (br s, 4H), 3.13 (br s, 4H).

Example 132 N-(2-Phenylethyl)-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.48 (br s, 1H), 9.58 (br s, 2H), 8.26 (br s, 1H), 7.91 (d, J=7.2 Hz, 1H), 7.30-7.18 (m, 5H), 6.50 (d, J=7.2 Hz, 1H), 3.97 (br s, 4H), 3.58-3.54 (m, 2H), 3.18 (br s, 4H), 2.82 (t, J=7.2 Hz, 2H).

Example 133 N-Bicyclo[2.2.1]hept-2-yl-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.38 m/z found, 274.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 9.43 (br, s, 1H), 8.48 (d, J=4.8 Hz, 1H), 7.95 (br, s, 1H), 6.54 (d, J=7.2 Hz, 1H), 4.01 (br, s, 5H), 3.70-3.52 (m, 4H), 2.27-2.21 (m, 2H), 1.79-1.72 (m, 1H), 1.48-1.16 (m, 7H).

Example 134 4-Piperazin-1-yl-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.80 (d, J=7.5 Hz, 1H), 6.54 (d, J=7.2 Hz, 1H), 4.42 (br, s, 1H), 4.11 (br, s, 4H), 3.61-3.58 (m, 1H), 3.38-3.03 (m, 4H), 2.67 (m, 1H), 2.50-2.48 (m, 1H), 2.05-2.00 (m, 2H), 1.91-1.83 (m, 2H), 1.73-1.66 (m, 1H), 1.25 (s, 3H), 1.16 (d, J=7.2 Hz, 3H), 1.07 (s, 3H), 1.04-1.00 (m, 1H).

Example 135 3-({4-[3-(Methylamino)azetidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=72 Hz, 1H), 6.01 (d, J=7.2 Hz, 1H), 4.62-4.59 (m, 2H), 4.40-4.26 (m, 3H), 3.67-3.43 (m, 4H), 1.85-1.79 (m, 2H).

Example 136 2,2-Dimethyl-3-({4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₃N₅O, 265.36 m/z found, 266.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.71 (d, J=7.2 Hz, 1H), 6.05 (d, J=6.9 Hz, 1H), 4.58-4.52 (m, 2H), 4.32-4.22 (m, 3H), 2.73 (s, 3H), 0.90 (s, 6H).

Example 137 3-[(4-Piperazin-1-ylpyrimidin-2-yl)amino]propan-1-ol

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.71 (d, J=7.5 Hz, 1H), 6.44 (d, J=7.2 Hz, 1H), 4.16 (br s, 2H), 3.89 (br s, 2H), 3.59-3.44 (m, 4H), 3.28-3.25 (m, 4H), 1.79-1.71 (m, 2H).

Example 138 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(2-methylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.52 (d, J=7.2 Hz, 1H), 6.05 (br s, 1H), 4.43-4.30 (m, 1H), 4.17-3.13 (m, 9H), 2.29-2.22 (m, 1H), 1.99-1.93 (m, 1H), 1.91-1.77 (m, 1H), 0.82 (d, J=6.6 Hz, 6H).

Example 139 N-Cyclopentyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.38 m/z found, 274.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=6.0 Hz, 1H), 6.22 (br s, 1H), 4.44-3.43 (m, 9H), 2.34 (m, 1H), 2.07 (br s, 3H), 1.77-1.62 (m, 6H).

Example 140 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(2-methoxyethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅O, 263.35 m/z found, 264.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.54 (d, J=7.2 Hz, 1H), 6.09-6.06 (m, 1H), 4.43-4.15 (m, 2H), 3.91-3.27 (m, 10H), 3.55 (s, 3H), 2.26-2.24 (m, 1H), 1.96-1.93 (m, 1H).

Example 141 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-[(1R)-1-phenylethyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₃N₅, 309.42 m/z found, 310.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.63 (d, J=6.9 Hz, 1H), 7.38-7.13 (m, 5H), 6.12 (d, J=7.2 Hz, 1H), 5.03 (br s, 1H), 4.37-4.17 (m, 2H), 3.95-3.72 (m, 2H), 3.51-3.33 (m, 4H), 2.28-2.19 (m, 1H), 1.98-1.94 (m, 1H), 1.48 (d, J=7.2 Hz, 3H).

Example 142 N-(4-Fluorobenzyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₀FN₅, 313.38 m/z found, 314.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.55 (d, J=7.2 Hz, 1H), 7.33-7.29 (m, 2H), 7.05-6.99 (m, 2H), 6.08-6.04 (m, 1H), 4.55 (s, 2H), 4.44-4.35 (m, 1H), 4.11-3.32 (m, 7H), 2.26-2.24 (m, 1H), 1.91 (m, 1H).

Example 143 N-Cyclopropyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₁₉N₅, 245.33 m/z found, 246.1 [M+H]^(+l .) ¹H NMR (300 MHz, CD₃OD): 7.69 (d, J=7.2 Hz, 1H), 6.24 (d, J=7.5 Hz, 1H), 4.39-3.79 (m, 4H), 3.60-3.34 (m, 4H), 2.60-2.50 (m, 1H), 2.30-2.22 (m, 1H), 2.00-1.90 (m, 1H), 0.84 (m, 2H), 0.57 (br s, 2H).

Example 144 N-(4-Methoxybenzyl)-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅O, 299.38 m/z found, 300.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=7.5 Hz, 1H), 7.20 (d, J=8.7 Hz, 2H), 6.81 (d, J=8.4 Hz, 2H), 6.45 (d, J=7.2 Hz, 1H), 4.46 (s, 2H), 4.13 (br s, 2H), 3.89 (br s, 2H), 3.68 (s, 3H), 3.22 (br s, 4H).

Example 145 N-Cyclopropyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=7.5 Hz, 1H), 6.28 (d, J=7.5 Hz, 1H), 3.97-3.49 (m, 5H), 2.75 (s, 3H), 2.65-2.33 (m, 3H), 0.92-0.85 (m, 2H), 0.63 (s, 2H).

Example 146 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-bicyclo[2.2.1]hept-2-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.38 m/z found, 274.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.28 (s, 1H), 4.10-3.81 (m, 6H), 2.56-2.53 (m, 1H), 2.36-2.20 (m, 2H), 1.93-1.86 (m, 1H), 1.81-1.24 (m, 8H).

Example 147 N-Bicyclo[2.2.1]hept-2-yl-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.38 m/z found, 274.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.15 (d, J=7.2 Hz, 1H), 4.67-4.31 (m, 5H), 3.60-3.50 (m, 1H), 2.83 (s, 3H), 2.39-2.33 (m, 2H), 1.98-1.86 (m, 1H), 1.62-1.49 (m, 4H), 1.35-1.20 (m, 3H).

Example 148 3-({4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-yl}amino)-2,2-dimethylpropan-1-ol

MS (ESI): mass calcd. for C₁₅H₂₅N₅O, 291.4 m/z found, 292.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=7.5 Hz, 1H), 6.20 (d, J=5.4 Hz, 1H), 4.43-4.38 (m, 1H), 4.38-4.24 (m, 1H), 4.00-3.84 (m, 2H, 3.70-3.50 (m, 1H), 3.42-3.26 (m, 6H), 2.36-2.26 (m, 1H), 2.04 (br, s, 1H), 0.91 (s, 6H).

Example 149 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.2 Hz, 1H), 6.28-6.26 (m, 1H), 4.15-3.69 (m, 5H), 3.39-3.32 (m, 2H), 2.61-2.46 (m, 1H), 2.29-2.22 (m, 2H), 1.82-1.62 (m, 6H), 1.34-1.31 (m, 2H).

Example 150 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4,4,4-trifluorobutyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₈F₃N₅, 289.31 m/z found, 290.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.31-6.27 (m, 1H), 4.08-3.70 (m, 5H), 3.60-3.55 (m, 2H), 2.59-2.47 (m, 1H), 2.34-2.21 (m, 3H), 1.97-1.88 (m, 2H).

Example 151 3-{[4-(3-Aminoazetidin-1-yl)pyrimidin-2-yl]amino}-2,2-dimethylpropan-1-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.73 (d, J=7.5 Hz, 1H), 6.08 (d, J=6.9 Hz, 1H), 4.64-4.59 (m, 2H), 4.35-4.26 (m, 3H), 3.39-3.29 (m, 4H), 0.94 (s, 6H).

Example 152 3-({4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.65 (d, J=7.2 Hz, 1H), 6.16 (d, J=6.9 Hz, 1H), 3.94-3.46 (m, 9H), 2.71 (s, 3H), 2.50-2.40 (m, 1H), 2.27-2.15 (m, 1H), 1.80-1.71 (m, 2H).

Example 153 3-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2,2-dimethylpropan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₃N₅O, 265.36 m/z found, 266.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.73 (d, J=7.5 Hz, 1H), 6.08 (d, J=6.9 Hz, 1H), 4.64-4.59 (m, 2H), 4.35-4.26 (m, 3H), 3.39-3.29 (m, 4H), 0.94 (s,6H).

Example 154 3-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.73 (d, J=7.5 Hz, 1H), 6.26 (d, J=6.9 Hz, 1H), 4.05-3.54 (m, 9H), 2.65-2.40 (m, 1H), 2.38-2.05 (m, 1H), 1.90-1.81 (m, 2H).

Example 155 3-{[4-(3-Aminoazetidin-1-yl)pyrimidin-2-yl]amino}propan-1-ol

MS (ESI): mass calcd. for C₁₀H₁₇N₅O, 223.28 m/z found, 224.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.71 (d, J=7.2 Hz, 1H), 6.09 (d, J=6.6 Hz, 1H), 4.62-4.60 (m, 2H), 4.33-4.26 (m, 3H), 3.65 (t, J=6.3 Hz, 2H), 3.51 (br, s, 2H), 1.85-1.79 (m, 2H).

Example 156 N-(4-Methylbenzyl)-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.81 (d, J=7.2 Hz, 1H), 7.25-7.15 (m, 4H), 6.54 (d, J=7.5 Hz, 1H), 4.57 (s, 2H), 4.19 (br, s, 2H), 3.96 (br, s, 2H), 3.31-3.29 (m, 4H), 2.31 (s, 3H).

Example 157 4-Piperazin-1-yl-N-(pyridin-2-ylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₁₈N₆, 270.34 m/z found, 271.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.82 (d, J=5.7 Hz, 1H), 8.62 (t, J=7.5 Hz, 1H), 8.14 (d, J=7.5 Hz, 1H), 8.02 (t, J=6.6 Hz, 1H), 7.94 (d, J=7.5 Hz, 1H), 6.65 (d, J=7.5 Hz, 1H), 5.12 (s, 2H), 3.99 (br, s, 4H).

Example 158 2,2-Dimethyl-3-({4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₄H₂₅N₅O, 279.39 m/z found, 280.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.71 (d, J=7.2 Hz, 1H), 6.22 (s, 1H), 3.99-3.96 (m, 3H), 3.88-3.68 (m, 2H), 3.43-3.26 (m, 4H), 2.76 (s, 3H), 2.57-2.31 (m, 2H), 0.95 (m, 6H).

Example 159 3-({4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₁N₅O, 263.35 m/z found, 264.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.64 (d, J=7.5 Hz, 1H), 6.15 (d, J=7.2 Hz, 1H), 4.41-4.17 (m, 2H), 4.01-3.79 (m, 2H), 3.65-3.28 (m, 8H), 2.30-2.23 (m, 1H), 2.00-1.95 (m, 1H), 1.78-1.74 (m, 2H).

Example 160 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.35 m/z found, 248.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.46 (d, J=7.2 Hz, 1H), 5.99 (d, J=8.7 Hz, 1H), 4.01-3.96 (m, 2H), 3.81-3.57 (m, 4H), 2.40-2.36 (m, 1H), 2.14-2.08 (m, 1H), 1.84-1.78 (m, 2H), 1.54-1.44 (m, 6H).

Example 161 3-{[4-(4-Methylpiperazin-1-yl)pyrimidin-2-yl]amino}propan-1-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=7.5 Hz, 1H), 6.46 (d, J=7.5 Hz, 1H), 3.59-3.47 (m, 8H), 3.27-3.20 (m, 4H), 2.88 (s, 3H), 1.79-1.71 (m, 2H).

Example 162 N-Bicyclo[2.2.1]hept-2-yl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₅N₅, 287.41 m/z found, 288.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=6.8 Hz, 1H), 6.31 (br s, 1H), 4.05-3.63 (m, 6H), 2.85 (s, 3H), 2.61-2.37 (m, 4H), 1.89-1.21 (m, 3H).

Example 163 N-(4-Methylbenzyl)-4-(4-methylpiperazin-2-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.1 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 8.76 (s, 1H), 8.00 (d, J=6.9 Hz, 1H), 7.28 (d, J=7.8 Hz, 2H), 7.18 (d, J=7.8 Hz, 2H), 6.58 (d, J=6.9 Hz, 1H), 4.55 (d, J=5.4 Hz, 2H), 3.60-3.00 (m, 4H), 2.79 (s, 3H), 2.60-2.40 (m, 4H), 2.31 (s, 3H).

Example 164 4-(4-Methylpiperazin-1-yl)-N-[2-(methylsulfanyl)ethyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅S, 257.4 m/z found, 268.1 [M+H]⁺. Amine ¹H NMR (300 MHz, CDCl₃): 7.87 (d, J=6.0 Hz, 1H), 5.89 (d, J=6.0 Hz, 1H), 5.25 (s, 1H), 3.61-3.55 (m, 6H), 2.73 (t, J=6.6 Hz, 2H), 2.46-2.43 (m, 4H), 2.33 (s, 3H), 2.14 (s, 3H) Salt ¹H NMR (300 MHz, CD₃OD): 7.87 (d, J=7.5 Hz, 1H), 6.60 (d, J=7.5 Hz, 1H), 3.00 (s, 3H), 2.80 (t, J=6.6 Hz, 3H), 2.18 (s, 3H).

Example 165 N-Benzyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.0 [M+H]⁺. Amine ¹H NMR (300 MHz, CDCl₃): 7.89 (d, J=6.3 Hz, 1H), 7.36-7.24 (m, 5H), 5.90 (d, J=6.0 Hz, 1H), 5.19 (br s, 1H), 4.59 (d, J=5.7 Hz, 2H), 3.59-3.57 (m, 4H), 2.44-2.41 (m, 4H), 2.32 (s, 3H) Salt ¹H NMR (300 MHz, CD₃OD): 7.88 (d, J=6.6 Hz, 1H), 7.40-7.34 (m, 5H), 6.61 (d, J=6.0 Hz, 1H), 5.07-4.43 (m, 4H), 4.67 (s, 2H), 3.66-3.11 (m, 4H), 2.99 (s, 3H).

Example 166 2,2-Dimethyl-3-[(4-piperazin-1-ylpyrimidin-2-yl)amino]propan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₃N₅O, 265.38 m/z found, 266.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.81 (d, J=7.5 Hz, 1H), 6.53 (d, J=6.9 Hz, 1H), 4.26 (br, s, 2H), 4.00 (br, s, 2H), 3.42-3.29 (m, 8H), 0.95 (s, 6H).

Example 167 3-({4-[(3R)-3-(Methylamine)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.2 Hz, 1H), 6.28 (d, J=7.5 Hz, 1H), 4.09-3.57 (m, 9H), 2.83 (s, 3H), 2.62-2.55 (m, 1H), 2.50-2.30 (m, 1H), 1.92-1.83 (m, 2H).

Example 168 4-(4-Methylpiperazin-1-yl)-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₉H₃₁N₅, 329.49 m/z found, 330.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.85 (d, J=7.5 Hz, 1H), 6.59 (d, J=7.5 Hz, 1H), 4.86-4.80 (m, 2H), 4.60-4.40 (m, 2H), 3.80-3.20 (m, 5H), 3.04 (s, 3H), 2.78-2.54 (m, 2H), 2.13-1.74 (m, 4H), 1.35 (s, 3H), 1.23 (d, J=7.2 Hz, 3H), 1.15 (s, 3H), 1.20-1.07 (m, 1H).

Example 169 2,2-Dimethyl-3-({4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₄H₂₅N₅O, 279.39 m/z found, 280.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.5 Hz, 1H), 6.25 (d, J=6.0 Hz, 1H), 4.04-3.73 (m, 5H), 3.43-3.30 (m, 4H), 2.80 (s, 3H), 2.59-2.36 (m, 2H), 0.95 (s, 6H).

Example 170 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(4-methylbenzyl)pyrimidin-20amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.78 (s, br, 1H), 7.28 (s, br, 2H), 7.21 (s, br, 2H), 6.29 (s, br, 1H), 4.62 (s, 2H), 4.03-3.69 (m, 5H), 2.82 (s, 3H), 2.58 (m, 1H), 2.38 (m, 1H), 2.35 (s, 3H).

Example 171 4-[3-(Methylamino)azetidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.72 (d, J=7.2 Hz, 1H), 6.09 (br s, 1H), 4.62-4.27 (m, 5H), 2.77 (s, 3H), 1.95-1.90 (m, 1H), 0.97 (d, J=6.3 Hz, 6H) D2O: 7.53 (d, J=7.2 Hz, 1H), 5.91 (br s, 1H), 4.60-4.50 (m, 2H), 4.32-4.21 (m, 3H), 3.12 (br s, 2H), 2.69 (s, 3H), 1.83-1.79 (m, 1H), 0.83 (d, J=6.9 Hz, 6H).

Example 172 N-Cyolopentyl-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.35 m/z found, 248.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.71 (d, J=7.2 Hz, 1H), 6.10 (d, J=7.2 Hz, 1H), 4.62-4.28 (m, 5H), 2.77 (s, 3H), 2.06-2.02 (m, 2H), 1.78-1.57 (m, 6H).

Example 173 4-(4-Methylpiperazin-1-yl)-N-(2-phenylethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.56 (d, J=7.5 Hz, 1H), 7.26-7.20 (m, 5H), 6.22 (d, J=7.2 Hz, 1H), 5.00-4.50 (m, 4H), 3.80-3.60 (m, 2H), 3.40-3.15 (m, 4H), 2.90-2.70 (m, 5H).

Example 174 N-Benzyl-4-[(3R)-3-(methylamine)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.78 (d. J=7.2 Hz, 1H), 7.38-7.32 (m, 5H), 6.28 (d, J=7.2 Hz, 1H), 4.65 (s, 2H), 4.10-3.70 (m, 5H), 2.79 (s, 3H), 2.58-2.46 (m, 2H).

Example 175 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1R)-1-phenylethyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.1 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 7.76 (d, J=7.2 Hz, 1H), 7.50-7.30 (m, 5H), 6.24 (t, J=7.8 Hz, 1H), 5.16 (br s, H), 4.20-3.60 (m, 5H), 2.50 (m, 1H), 2.25 (m, 1H), 1.59 (d, J=6.9 Hz, 3H).

Example 176 N-(4-Methoxybenzyl)-4-[(3R)-30(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅O, 313.41 m/z found, 314.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=6.6 Hz, 1H), 7.33 (d, J=7.5 Hz, 2H), 6.94 (d, J=7.5 Hz, 2H), 6.29 (d, J=6.9 Hz, 1H), 4.61 (s, 2H), 4.10-3.80 (m, 5H), 3.81 (s, 3H), 2.59 (s, 3H), 2.70-2.50 (m, 1H), 2.40-2.20 (m, 1H).

Example 177 2-Methyl-1-[(4-piperazin-1-ylpyrimidin-2-yl)amino]propan-2-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.74 (d, J=7.2 Hz, 1H), 6.46 (d, J=7.2 Hz, 1H), 4.16 (br s, 2H), 3.91 (br s, 2H), 3.37-3.25 (m, 6H), 1.16 (s, 6H).

Example 178 N-(4-Fluorobenzyl)-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₈FN₅, 287.34 m/z found, 288.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 7.43-7.38 (m, 2H), 7.13-7.07 (m, 2H), 6.13 (d, J=7.2 Hz, 1H), 4.70-4.50 (m, 2H), 4.60 (s, 2H), 4.40-4.28 (m, 3H), 2.79 (s, 3H).

Example 179 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-benzylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.74 (d, J=7.2 Hz, 1H), 7.43-7.27 (m, 5H), 6.27-6.22 (m, 1H), 4.62 (s, 2H), 4.09-3.52 (m, 5H), 2.56-2.41 (m, 1H), 2.25-2.15 (m, 1H).

Example 180 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R)-1-phenylethyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 8.60 (br s, 1H), 7.86 (d, J=7.2 Hz, 1H), 7.44-7.25 (m, 5H), 6.16 (d, J=7.5 Hz, 1H), 5.15-5.11 (m, 1H), 3.91-3.54 (m, 5H), 2.57 (s, 3H), 2.38-2.27 (m, 2H), 1.53 (d, J=6.9 Hz, 3H).

Example 181 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclohexylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.2 Hz, 1H), 6.27 (dd, J=7.2, 6.9 Hz, 1H), 4.20-3.60 (m, 6H), 2.61-2.48 (m, 1H), 2.31-2.22 (m, 1H), 2.08-1.69 (m, 5H), 1.60-1.20 (m, 6H).

Example 182 N-(2-Methoxyethyl)-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.79 (d, J=7.2 Hz, 1H), 6.16 (d, J=7.2 Hz, 1H), 4.72-4.61 (m, 2H), 4.47-4.33 (m, 3H), 3.63 (br s, 4H), 3.43 (s, 3H), 2.80 (s, 3H).

Example 183 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-phenylethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.1 [M+H]⁺. Amine ¹H NMR (300 MHz, CDCl₃): 7.82 (d, J=6.0 Hz, 1H), 7.33-7.23 (m, 5H), 5.68 (d, J=8.0 Hz, 1H), 4.91 (br s, 1H), 3.66-3.30 (m, 7H), 2.90 (t, J=7.2 Hz, 2H), 2.48 (s, 3H), 2.48-2.14 (m, 1H), 1.90-1.80 (m, 1H) Salt ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=6.6 Hz, 1H), 7.40-7.20 (m, 5H), 6.28 (d, J=6.6 Hz, 1H), 4.20-3.60 (m, 7H), 3.10-2.90 (m, 2H), 2.85 (s, 3H), 2.70-2.20 (m, 2H)

Example 184 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyolo[3.1.1]hept-3-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₉H₃₁N₅, 329.49 m/z found, 330.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=6.6 Hz, 1H), 6.28 (d, J=6.6 Hz, 1H), 4.05-3.56 (m, 6H), 2.84 (s, 3H), 2.73-2.20 (m, 3H), 2.05-1.78 (m, 5H), 1.32 (s, 3H), 1.27-1.05 (m, 7H).

Example 185 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-methoxybenzyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅O, 299.38 m/z found, 300.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.2 Hz, 1H), 7.30 (d, J=8.1 Hz, 2H), 6.91 (d, J=7.8 Hz, 2H), 6.27 (t, J=7.2 Hz, 1H), 4.57 (s, 2H), 4.20-3.70 (m, 5H), 3.79 (s, 3H), 2.60-2.20 (m, 2H).

Example 186 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-methylbenzyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.78 (d, J=7.5 Hz, 1H), 7.28 (d, J=7.5 Hz, 2H), 7.19 (d, J=7.5 Hz, 2H), 6.40-6.20 (m, 1H), 4.62 (s, 2H), 4.20-3.70 (m, 5H), 2.50-2.40 (m, 1H), 2.35 (s, 3H), 3.25-2.20 (m, 1H).

Example 187 N-(Cyclopentylmethyl)-4-piperazin-1-ylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.5 Hz, 1H), 6.49 (d, J=7.2 Hz, 1H), 4.20 (br, s, 2H), 3.95 (br, s, 2H), 3.35-3.26 (m, 6H), 2.19-2.14 (m, 1H), 1.77 (br, 2H), 1.64-1.56 (m, 4H), 1.28-1.22 (m, 2H).

Example 188 4-[3-(Methylamino)azetidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₁₈N₆, 270.34 m/z found, 271.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.64 (d, J=4.8 Hz, 1H), 8.19-8.14 (m, 1H), 7.81-7.61 (m, 3H), 6.13 (d, J=7.2 Hz, 1H), 4.57-4.55 (m, 1H), 4.38 (br, s, 2H), 4.21 (br, s, 2H), 2.73 (s, 3H).

Example 189 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(3S,5S,7S)-tricyclo[3.3.1.1.3.7]dec-1-ylmethyl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₁N₅, 341.5 m/z found, 342.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.93 (d, J=7.2 Hz, 1H), 6.43 (d, J=6.9 Hz, 1H), 4.28-3.91 (m, 5H), 3.38 (s, 2H), 2.99 (s, 3H), 2.78-2.70 (m, 1H), 2.56-2.45 (m, 1H), 2.18 (s, 3H), 1.99-1.85 (m, 6H), 1.78 (s, 6H).

Example 190 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₉H₃₁N₅, 329.49 m/z found, 330.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.94 (d, J=7.5 Hz, 1H), 6.42 (d, J=7.5 Hz, 1H), 4.70-4.60 (m, 1H), 4.30-3.90 (m, 5H), 2.98 (s, 3H), 2.80-2.40 (m, 3H), 2.20-1.40 (m, 6H), 1.21 (s, 3H), 1.13 (s, 3H), 1.08 (s, 3H).

Example 191 N-(Cyclohexylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₇N₅, 289.43 m/z found, 290.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (d, J=7.2 Hz, 1H), 6.30-6.20 (m, 1H), 4.10-3.75 (m, 5H), 3.40-3.30 (m, 2H), 2.83 (s, 3H), 2.62-2.56 (m, 1H), 2.45-2.38 (m, 1H), 1.90-1.60 (m, 6H), 1.40-0.99 (m, 5H).

Example 192 N-Cyclohexyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.76 (d, J=7.2 Hz, 1H), 6.24 (d, J=6.9 Hz, 1H), 4.10-3.70 (m, 6H), 2.81 (s, 3H), 2.80-2.30 (m, 2H), 2.06-1.70 (m, 5H), 1.49-1.33 (m, 5H).

Example 193 N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₉H₃₁N₅, 329.49 m/z found, 330.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.68 (d, J=7.5 Hz, 1H), 6.20 (d J=7.2 Hz, 1H), 4.10-3.40 (m, 6H), 2.89 (d, J=7.8 Hz, 1H), 2.75 (s, 3H), 2.60-2.20 (m, 3H), 2.03-1.90 (m, 6H), 1.57-1.50 (m, 1H), 1.20 (s, 3H), 1.06 (s, 3H), 0.91 (d, J=9.9 Hz, 1H).

Example 194 4-(1,4-Diazepan-1-yl)-N-(2,2-dimethylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.39 m/z found, 264.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.84 (d, J=7.5 Hz, 1H), 6.53 (d, J=7.5 Hz, 1H), 4.29-4.08 (m, 3H), 3.89-3.85 (m, 1H), 3.60-3.20 (m, 6H), 2.33-2.24 (m, 2H), 1.04 (s, 9H).

Example 195 N-Bicyclo[2.2.1]hept-2-yl-4-(1,4-diazepan-1-yl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₅N₅, 287.41 m/z found, 288.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.82 (d, J=7.5 Hz, 1H), 6.53 (d, J=7.5 Hz, 1H), 4.30-3.70 (m, 5H), 3.60-3.40 (m, 4H), 2.40-2.20 (m, 4H), 1.93-1.87 (m, 1H), 1.71-1.23 (m, 7H)

Example 196 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-butylpyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.2 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.64 (d, J=7.2 Hz, 1H), 6.19 (s, 1H), 3.72-4.21 (m, 5H), 3.38-3.44 (s, 2H), 2.49-2.60 (m, 1H), 2.25-2.34 (m, 1H), 1.58-1.66 (m, 2H), 1.37-1.44 (m, 2H), 0.92-0.97 (t J=7.2 Hz, 3H).

Example 197 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclohexylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.75 (d, J=7.5 Hz, 1H), 6.27 (d, J=7.5 Hz, 1H), 4.14-3.68 (m, 5H), 2.61-2.49 (m, 1H), 2.31-2.21 (m, 1H), 1.79-1.69 (m, 6H), 1.28-1.16 (m, 4H), 1.04-0.97 (m, 2H).

Example 198 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.51 (d, J=7.2 Hz, 1H), 6.07 (s, 1H), 4.07-4.09 (m, 1H), 3.60-3.95 (m, 4H), 3.15 (s, 2H), 2.34-2.49 (m, 1H), 2.10-2.23 (m, 1H), 0.83 (d, J=6.6 Hz, 6H).

Example 199 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(4-fluorobenzyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₅H₁₈FN₅, 287.34 m/z found, 288.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.49 (d, J=7.5 Hz, 1H), 7.24-7.29 (m, 2H), 6.95 (m, 2H), 5.98 (m, 1H), 4.45 (s, 2H), 3.95-4.04 (m, 1H), 3.56-3.82 (m, 4H), 2.20-2.41 (m, 1H), 1.98-2.18 (m, 1H).

Example 200 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₀N₆, 284.37 m/z found, 285.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.81 (s, 1H), 8.58 (s, 1H), 8.13 (d, J=8.3 Hz, 1H), 7.97 (s, 1H), 7.87 (d, J=4.8 Hz, 1H), 6.35 (d, J=6.3 Hz, 1H), 5.06 (s, 2H), 4.00-3.54 (m, 5H), 2.76 (s, 3H), 2.54-2.24 (m, 2H).

Example 201 N-Cyclopentyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.51 (d, J=7.2 Hz, 1H), 6.07 (s, 1H), 3.83-4.09 (m, 3H), 3.64-3.76 (m, 3H), 2.70 (s, 3H), 2.40-2.50 (m, 1H), 2.17-2.27 (m, 1H), 1.90-1.93 (m, 2H), 1.50-1.60 (m, 6H).

Example 202 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.36 m/z found, 250.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.53 (d, J=7.2 Hz, 1H), 6.05 (br s, 1H), 3.91-3.63 (m, 5H), 2.70 (s, 3H), 2.50-2.38 (m, 1H), 2.26-2.15 (m, 1H), 1.87-1.78 (m, 1H), 0.84 (d, J=6.6 Hz, 6H).

Example 203 N-(2,2-Dimethylpropyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.39 m/z found, 264.1 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 7.54 (d, J=7.2 Hz, 1H), 6.05 (s, 1H), 3.75-3.91 (m, 3H), 3.82-3.71 (m, 3H), 3.18-3.26 (m, 2H), 2.70 (s, 3H), 2.38-2.50 (m, 1H), 2.15-2.28 (m, 1H), 0.85 (s, 9H).

Example 204 N-Benzyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, MISSING ¹H NMR (300 MHz, CD₃OD): 7.79 (d, J=7.2 Hz, 1H), 7.41-7.31 (m, 5H), 6.30 (d, J=6.9 Hz, 1H), 4.68 (s, 2H), 4.06-3.77 (m, 5H), 2.82 (s, 3H), 2.62-2.21 (m, 2H).

Example 205 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1r,5R,7S)-tricyclo[3.3.1.1.3.7]dec-2-yl]pyrimidin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₇N₅, 313.45 m/z found, 314.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.81 (d, J=7.5 Hz, 1H), 6.28 (t, J=7.2 Hz, 1H), 4.20-3.61 (m, 6H), 2.60-2.49 (m, 1H), 2.31-2.21 (m, 1H), 2.10-1.72 (m, 14H).

The compounds in Example 206 through Example 253 were prepared using methods analogous to those described in Example 21 Method B.

Example 206 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.62 (d, J=7.5 Hz, 1H), 6.42 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.93 (s, 1H), 4.11-3.69 (m, 6H), 2.88 (s, 3H), 2.67-2.57 (m, 2H), 2.43-2.39 (m, 1H), 2.00-1.35 (m, 6H), 1.11 (s, 3H), 1.02 (s, 3H), 0.98 (s, 3H).

Example 207 Adamantan-2-yl-[4-(4-methyl-piperazin-1-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₀H₃₀N₄, 326.49 m/z found, 327.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.65 (d, J=7.8 Hz, 1H), 6.67 (dd, J=2.1 Hz, 7.8 Hz, 1H), 6.32 (s, 1H), 4.30 (d, J=14 Hz, 2H), 3.86 (s, 1H), 3.68 (d, J=12 Hz, 2H), 3.50 (t, J=13 Hz, 2H), 3.40-3.20 (m, 2H), 2.99 (s, 3H), 2.20-1.70 (m, 14H).

Example 208 Adamantan-2-yl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₀H₃₀N₄, 326.49 m/z found, 327.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.65 (d, J=7.5 Hz, 1H), 6.43 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.96 (d, J=2.1 Hz, 1H), 4.12-3.69 (m, 6H), 2.88 (s, 3H), 2.66-2.59 (m, 1H), 2.42-2.35 (m, 1H), 2.20-1.75 (m, 14H).

Example 209 N-[(1R)-1-Cyclohexylethyl]-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₈H₃₀N₄, 302.47 m/z found, 303.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.5 Hz, 1H), 6.37 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.81 (d, J=2.4 Hz, 1H), 4.08-3.53 (m, 6H), 2.84 (s, 3H), 2.82-2.55 (m, 1H), 2.39-2.35 (m, 1H), 1.91-1.71 (m, 5H), 1.60-1.05 (m, 8H), 1.24 (d, J=6.8 Hz, 3H).

Example 210 Adamantan-1-yl-[4-(3S)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₀H₃₀N₄, 326.49 m/z found, 327.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.53 (d, J=7.5 Hz, 1H), 6.31 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.80 (s, 1H), 4.00-3.50 (m, 5H), 2.73 (s, 3H), 2.50-2.46 (m, 1H), 2.30-2.20 (m, 1H), 2.13 (s, 3H), 2.01 (s, 6H), 1.75 (s, 6H).

Example 211 N-(Cyclohexylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₈N₄, 288.44 m/z found, 289.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.2 Hz, 1H), 6.37 (dd, J=2.4 Hz, 7.2 Hz, 1H), 5.78 (d, J=2.4 Hz, 1H), 4.04-3.60 (m, 5H), 3.12 (d, J=7.2 Hz, 2H), 2.82 (s, 3H), 2.58-2.53 (m, 1H), 2.40-2.20 (m, 1H), 1.87-1.64 (m, 6H), 1.40-1.02 (m, 5H).

Example 212 N-(Cyclohexylmethyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₈N₄, 288.44 m/z found, 289.3 [M+H]⁺. ¹H NMR (300 MHz, CO₃OD): 7.63 (d, J=7.2 Hz, 1H), 6.68 (d, J=7.8 Hz, 1H), 6.17 (s, 1H), 4.32 (d, J=14.1 Hz, 2H), 3.69 (d, J=12.8 Hz, 2H), 3.50 (t, J=13.6 Hz, 2H), 3.34-3.23 (m, 2H), 3.18 (d, J=7.2 Hz, 2H), 3.01 (s, 3H), 1.90-1.66 (m, 6H), 1.37-1.30 (m, 3H), 1.13-1.05 (m, 2H).

Example 213 N-[(1R)-1-Cyclohexylethyl]-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₈H₃₀N₄, 302.47 m/z found, 303.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.58 (d, J=7.2 Hz, 1H), 6.39 (d, J=7.5 Hz, 1H), 5.83 (s, 1H), 4.08-3.55 (m, 6H), 2.86 (s, 3H), 2.70-2.50 (m, 1H), 2.40-2.20 (m, 1H), 1.93-1.73 (m, 5H), 1.60-1.08 (m, 6H), 1.26 (d, J=6.3 Hz, 3H).

Example 214 N-[(1R)-1-Cyclohexylethyl]-4-(4-methylpiperazin-1-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₈H₃₀N₄, 302.47 m/z found, 303.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.61 (d, J=7.5 Hz, 1H), 6.65 (dd, J=2.4 Hz, 7.5 Hz, 1H), 6.18 (d, J=2.4 Hz, 1H), 4.30 (d, J=14 Hz, 2H), 3.70-3.46 (m, 5H), 3.40-3.20 (m, 2H), 3.00 (s, 3H), 1.91-1.71 (m, 5H), 1.60-1.05 (m, 6H), 1.25 (d, J=6.6 Hz, 3H).

Example 215 Adamantan-2-yl-[4-(3S)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₀H₃₀N₄, 326.49 m/z found, 327.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.65 (d, J=7.5 Hz, 1H), 6.43 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.96 (d, J=1.8 Hz, 1H), 4.12-3.69 (m, 6H), 2.88 (s, 3H), 2.67-2.59 (m, 1H), 2.43-2.36 (m, 1H), 2.20-1.75 (m, 14H).

Example 216 3-{[4-(4-Methylpiperazin-1-yl)pyridin-2-yl]amino}propan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.57 (d, J=7.5 Hz, 1H), 6.62-6.59 (m, 1H), 4.25 (d, J=14.4 Hz, 2H), 3.66-3.59 (m, 4H), 3.48-3.15 (m, 6H), 2.93 (s, 3H), 1.86-1.78 (m, 2H).

Example 217 N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.55 (d, J=7.2 Hz, 1H), 6.36 (dd, J=2.1 Hz, 7.2 Hz, 1H), 5.74 (s, 1H), 4.10-3.50 (m, 5H), 3.40-3.20 (m, 2H), 2.81 (s, 3H), 2.58-2.33 (m, 4H), 2.31-1.94 (m, 5H), 1.60-1.80 (m, 1H), 1.24 (s, 3H), 1.09 (s, 3H), 0.97 (d, J=9.9 Hz, 1H)

Example 218 Adamantan-1-yl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₀H₃₀N₄, 326.49 m/z found, 327.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.54 (d, J=7.5 Hz, 1H), 6.32 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.81 (d, J=2.1 Hz, 1H), 4.00-3.50 (m, 5H), 2.76 (s, 3H), 2.53-2.48 (m, 1H), 2.33-2.28 (m, 1H), 2.12 (br s, 3H), 2.01 (s, 6H), 1.75 (s, 6H).

Example 219 Adamantan-1-yl-[4-(4-methyl-piperazin-1-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₀H₃₀N₄, 326.49 m/z found, 327.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.8 Hz, 1H), 6.61 (dd, J=2.4 Hz, 7.5 Hz, 1H), 6.15 (d, J=2.1 Hz, 1H), 4.30-4.10 (m, 2H), 3.70-3.40 (m, 6H), 2.93 (s, 3H), 2.13 (s, 3H), 2.01 (s, 6H), 1.75 (t, J=14 Hz, 6H).

Example 220 Adamantan-1-ylmethyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₁H₃₂N₄, 340.52 m/z found, 341.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.61 (d, J=7.5 Hz, 1H), 6.41 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.91 (d, J=2.1 Hz, 1H), 4.12-3.69 (m, 5H), 3.05 (s, 2H), 2.88 (s, 3H), 2.66-2.59 (m, 1H), 2.43-2.40 (m, 1H), 2.36 (s, 3H), 1.82 (dd, J=12 Hz, 27 Hz, 6H), 1.70 (s, 6H).

Example 221 N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-(4-methylpiperazin-1-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.2 Hz, 1H), 6.64 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.74 (d, J=2.1 Hz, 1H), 4.27 (d, J=14 Hz, 2H), 3.64 (d, J=12 Hz, 2H), 3.45 (dd, J=14 Hz, 12 Hz, 2H), 3.40-3.20 (m, 4H), 2.97 (s, 3H), 2.43-2.38 (m, 2H), 2.04-1.94 (m, 5H), 1.60-1.50 (m, 1H), 1.24 (s, 3H), 1.09 (s, 3H), 0.98 (d, J=9.6 Hz, 1H).

Example 222 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄O, 276.38 m/z found, 277.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.62 (d, J=7.5 Hz, 1H), 6.43 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.85 (d, J=2.1 Hz, 1H), 4.08-3.61 (m, 10H), 2.86 (s, 3H), 2.70-2.50 (m, 1H), 2.45-2.35 (m, 1H), 2.10-2.00 (m, 2H), 1.70-1.69 (m, 2H).

Example 223 4-(4-Methylpiperazin-1-yl)-N-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄O, 276.38 m/z found, 277.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.67 (d, J=7.5 Hz, 1H), 6.64 (dd, J=2.4 Hz, 7.5 Hz, 1H), 6.21 (d, J=2.4 Hz, 1H), 4.35 (d, J=14 Hz, 2H), 4.05-4.01 (m, 2H), 3.88-3.48 (m, 7H), 3.40-3.20 (m, 2H), 3.04 (s, 3H), 2.10-1.90 (m, 2H), 1.72-1.64 (m, 2H).

Example 224 N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.55 (d, J=7.5 Hz, 1H), 6.36 (dd, J=2.1 Hz, 7.2 Hz, 1H), 5.74 (d, J=1.8 Hz, 1H), 4.10-3.60 (m, 5H), 3.40-3.20 (m, 2H), 2.81 (s, 3H), 2.80-2.20 (m, 4H), 2.10-1.90 (m, 5H), 1.70-1.50 (m, 1H), 1.24 (s, 3H), 1.09 (s, 3H), 0.97 (d, J=9.6 Hz, 1H).

Example 225 N-(Cyclohexylmethyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₈N₄, 288.44 m/z found, 289.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.2 Hz, 1H), 6.37 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.77 (d, J=2.4 Hz, 1H), 4.10-3.50 (m, 5H), 3.12 (d, J=6.9 Hz, 2H), 2.82 (s, 3H), 2.60-2.53 (m, 1H), 2.36-2.29 (m, 1H), 1.87-1.60 (m, 6H), 1.38-1.02 (m, 5H).

Example 226 N-(Cyclopentylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₆N₄, 274.41 m/z found, 275.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.2 Hz, 1H), 6.37 (d, J=7.2 Hz, 1H), 5.78 (s, 1H), 4.04-3.62 (m, 5H), 3.20 (d, J=7.2 Hz, 2H), 2.82 (s, 3H), 2.60-2.51 (m, 1H), 2.40-2.17 (m, 2H), 1.89-1.62 (m, 6H), 1.34-1.28 (m, 2H).

Example 227 N-(Cyclopentylmethyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₆N₄, 274.41 m/z found, 275.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.5 Hz, 1H), 6.37 (d, J=7.2 Hz, 1H), 5.78 (s, 1H), 4.04-3.62 (m, 5H), 3.20 (d, J=7.2 Hz, 2H), 2.82 (s, 3H), 2.58-2.53 (m, 1H), 2.36-2.19 (m, 2H), 1.89-1.62 (m, 6H), 1.34-1.30 (m, 2H).

Example 228 N-Cyclopentyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, 261.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.5 Hz, 1H), 6.37 (d, J=7.5 Hz, 1H), 5.76 (s, 1H), 4.05-3.62 (m, 6H), 2.82 (s, 3H), 2.60-2.53 (m, 1H), 2.39-2.33 (m, 1H), 2.11-2.06 (m, 2H), 1.83-1.56 (m, 6H).

Example 229 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₁N₅, 283.38 m/z found, 284.1 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.73 (br s, 1H), 9.60 (br s, 2H), 8.72 (d, J=4.5 Hz, 1H), 8.29-8.10 (m, 2H), 7.73-7.36 (m, 3H), 6.34 (d, J=5.7 Hz, 1H), 5.84 (s, 1H), 4.84 (d, J=5.1 Hz, 2H), 3.90-3.42 (m, 5H), 2.60 (s, 3H), 2.40-2.30 (m, 2H).

Example 230 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.39 (br s, 1H), 9.61 (br s, 2H), 8.05 (d, J=8.4 Hz, 1H), 7.66 (m, 1H), 6.29 (d, J=6.9 Hz, 1H), 5.75 (s, 1H), 3.96-3.40 (m, 6H), 2.60 (s, 3H), 2.50-2.30 (m, 3H), 12.07-1.51 (m, 5H), 1.23 (s, 3H), 1.05 (m, 7H).

Example 231 N-Bicyclo[2.2.1]hept-2-yl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₆N₄, 286.42 m/z found, 287.3 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.19 (br s, 1H), 9.59 (br s, 2H), 7.90 (d, J=6.0 Hz, 1H), 7.67 (br s, 1H), 6.28 (d, J=6.9 Hz, 1H), 5.65 (s, 1H), 3.89-3.50 (m, 6H), 2.59 (s, 3H), 2.33-2.17 (m, 4H), 1.85-1.79 (m, 1H), 1.48-1.09 (m, 7H).

Example 232 4-(4-Methylpiperazin-1-yl)-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.53 (d, J=7.5 Hz, 1H), 6.58 (d, J=7.8 Hz, 1H), 6.11 (s, 1H), 4.20 (d, J=14 Hz, 2H), 3.89-3.84 (m, 1H), 3.57 (d, J=12 Hz, 2H), 3.42 (t, J=13 Hz, 2H) 3.17 (t, J=13 Hz, 2H), 2.89 (s, 3H), 2.72-2.64 (m, 1H), 2.40-2.35 (m, 1H), 2.05-1.55 (m, 4H), 1.18 (s, 3H), 1.07 (d, J=7.2 Hz, 3H), 1.05-1.00 (m, 1H), 1.00 (s, 3H).

Example 233 N-tert-Butyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₄N₄, 248.37 m/z found, 249.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.55 (d, J=7.5 Hz, 1H), 6.34-6.31 (m, 1H), 5.77 (s, 1H), 4.01-3.59 (m, 5H), 2.77 (s, 3H), 2.532.49 (m, 1H), 2.33-2.29 (m, 1H), 1.43 (s, 9H).

Example 234 3-({4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]pyridin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.47 (d, J=7.5 Hz, 1H), 6.27 (d, J=7.2 Hz, 1H), 5.70 (br, 1H), 3.94-3.21 (m, 10H), 2.72 (s, 3H), 2.48-2.43 (m, 1H), 2.27-2.23 (m, 1H), 1.81-1.73 (m, 2H).

Example 235 N-Cyclopropyl-4-[(3S)-3-(methylamino)pyrrolidin-2-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₀N₄, 232.33 m/z found, 233.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.52 (d, J=7.5 Hz, 1H), 6.33 (dd, J=7.5 Hz, J=2.1 Hz, 1H), 5.76 (d, J=1.5 Hz, 1H), 3.96-3.52 (m, 4H), 2.52-2.41 (m, 2H), 2.30-2.21 (m, 1H), 0.88-0.82 (m, 2H), 0.56-0.51 (m, 2H).

Example 236 N-(Cyclopentylmethyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₆N₄, 274.41 m/z found, 275.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.61 (d, J=7.5 Hz, 1H), 6.66 (d, J=7.5 Hz, 1H), 6.16 (s, 1H), 4.29 (d, J=14 Hz, 2H), 3.66 (d, J=12 Hz, 2H), 3.48 (t, J=13 Hz, 2H), 3.40-3.20 (m, 2H), 3.22 (d, J=7.2 Hz, 2H), 2.98 (s, 3H), 2.27-2.17 (m, 1H), 1.90-1.62 (m, 6H), 1.34-1.30 (m, 2H).

Example 237 N-Benzyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₂N₄, 282.39 m/z found, 283.1 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.49 (br s, 1H), 9.53 (br s, 2H), 8.22 (s, 1H), 7.69 (s, 1H), 7.41-7.33 (m, 5H), 6.30 (d, J=6.9 Hz, 1H), 5.75 (s, 1H), 4.55 (d, J=5.4 Hz, 2H) 3.89-3.50 (m, 5H), 2.60 (s, 3H), 2.40-2.20 (m, 2H).

Example 238 N-(2-Methoxyethyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.5 Hz, 1H), 6.38 (dd, J=7.5 Hz, J=2.4 Hz, 1H), 5.83 (d, J=2.4 Hz, 1H), 4.05-4.02 (m, 1H), 3.93-3.89 (m, 2H), 3.71-3.32 (m, 6H), 3.31 (s, 3H), 2.82 (s, 3H), 2.61-2.54 (m, 1H), 2.37-2.30 (m, 1H).

Example 239 N-(2-Methoxyethyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.64 (d, J=7.5 Hz, 1H), 6.67 (dd, J=7.8 Hz, J=2.4 Hz, 1H), 6.20 (d, J=2.1 Hz, 1H), 4.3 (d, J=14.4 Hz, 2H), 3.67-3.21 (m, 13H), 2.98 (s,3H).

Example 240 2-Methyl-1-({4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-yl}amino)propan-2-ol

MS (ESI): mass calcd. C₁₄H₂₄N₄O, 264.37 m/z found, 265.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.2 Hz, 1H), 6.37 (br d, J=6.0 Hz, 1H), 5.88 (s, 1H), 4.03-3.63 (m, 5H), 3.26 (s, 2H), 2.82 (s, 3H), 2.58-2.53 (m, 1H), 2.36-2.32 (m, 1H), 1.29 (s, 6H).

Example 241 2-Methyl-1-{[4-(4-methylpiperazin-1-yl)pyridin-2-yl]amino}propan-2-ol

MS (ESI): mass calcd. for C₁₄H₂₄N₄O, 264.37 m/z found, 265.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.69 (d, J=7.8 Hz, 1H), 6.71 (br d, J=5.7 Hz, 1H), 6.30 (s, 1H), 4.36 (d, J=14 Hz, 2H), 3.72-3.48 (m, 6H), 3.30-3.20 (m, 2H), 3.03 (s, 3H), 1.34 (s, 6H).

Example 242 2-Methyl-1-({4-[(3S)-3-(methylamino)pyrrolidin-1 yl]pyridin-2-yl}amino)propan-2-ol

MS (ESI): mass calcd. for C₁₄H₂₄N₄O, 264.37 m/z found, 265.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.5 Hz, 1H), 6.36 (d, J=7.5 Hz, 1H), 5.87 (s, 1H), 4.06-3.63 (m, 5H), 3.27 (s, 2H), 2.83 (s, 3H), 2.61-2.51 (m, 1H), 2.40-2.31 (m, 1H), 1.30 (s, 6H).

Example 243 N-Butyl-4-[(3S)-3-(methylamino)pyrrolidin-2-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₄N₄, 248.37 m/z found, 249.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.2 Hz, 1H), 6.39 (d, J=8.9 Hz, 1H), 5.79 (s, 1H), 4.07-3.64 (m, 5H), 3.31 (t, J=7.2 Hz, 2H), 2.84 (s, 3H), 2.63-2.56 (m, 1H), 2.42-2.36 (m, 1H), 1.73-1.63 (m, 2H), 1.55-1.48 (m, 2H), 1.01 (t, J=7.5 Hz, 3H).

Example 244 4-(4-Methylpiperazin-1-yl)-N-(pyridin-2-ylmethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.89 (d, J=4.5 Hz, 1H), 8.62 (m, 1H), 8.13-8.05 (m, 2H), 7.80 (d, J=7.2 Hz, 1H), 6.82 (d, J=6.6 Hz, 1H), 6.37 (s, 1H), 5.16 (s, 2H), 4.43 (d, J=13 Hz, 2H), 3.69-3.53 (m, 4H), 3.30-3.20 (m, 2H), 3.01 (s, 3H).

Example 245 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-phenylethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₄N₄, 296.42 m/z found, 297.1 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.40 (br s, 1H), 9.64 (br s, 2H), 7.81 (s, 1H), 7.67 (s, 1H), 7.33-7.25 (m, 5H), 6.29 (s, 1H), 5.69 (s, 1H), 3.89-3.50 (m, 7H), 2.97-2.88 (m, 2H), 2.60 (s, 3H), 2.40-2.20 (m, 2H).

Example 246 N-(4-Fluorobenzyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₁FN₄, 300.38 m/z found, 301.1 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.57 (br s, 1H), 9.56 (br s, 2H), 8.25 (s, 1H), 7.69 (d, J=6.9 Hz, 1H), 7.48-7.43 (m, 2H), 7.25-7.19 (m, 2H), 6.30 (d, J=6.6 Hz, 1H), 5.73 (s, 1H), 4.54 (d, J=5.7 Hz, 2H), 3.89-3.61 (m, 5H), 2.59 (s, 3H), 2.40-2.20 (m, 2H).

Example 247 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.62 (d, J=7.2 Hz, 1H), 6.42 (dd, J=2.1 Hz, 7.2 Hz, 1H), 5.92 (d, J=2.1 Hz, 1H), 4.11-3.69 (m, 6H), 2.87 (s, 3H), 2.64-2.56 (m, 2H), 2.42-2.37 (m, 1H), 2.00-1.35 (m, 6H), 1.11 (s, 3H), 1.02 (s, 3H), 0.98 (s, 3H).

Example 248 N-Cyclopentyl-4-(4-methylpiperazin-1-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, MISSING ¹H NMR (300 MHz, CD₃OD): 7.60 (d, J=7.8 Hz, 1H), 6.64 (d, J=7.5 Hz, 1H), 6.11 (s, 1H), 4.27 (d, J=14 Hz, 2H), 3.99-3.97 (m, 1H), 3.64 (d, J=12 Hz, 2H), 3.45 (t, J=14 Hz, 2H), 3.22 (t, J=11 Hz, 2H), 2.97 (s, 3H), 2.09-2.05 (m, 2H), 2.18-1.57 (m, 6H).

Example 249 N-(4-Fluorobenzyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine

MS (ESI): mass calcd. C₁₇H₂₁FN₄, 300.38 m/z found, 301.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.66 (d, J=7.5 Hz, 1H), 7.47-7.42 (m, 2H), 7.17-7.12 (m, 2H), 6.70 (d, J=7.2 Hz, 1H), 6.16 (s, 1H), 4.55 (s, 2H), 4.30 (d, J=14 Hz, 2H), 3.67 (d, J=12 Hz, 2H), 3.47 (t, J=13 Hz, 2H), 3.24 (t, J=12 Hz, 2H), 2.99 (s, 3H).

Example 250 4-(4-Methylpiperazin-1-yl)-N-(2-phenylethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₄N₄, 296.42 m/z found, 297.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.66 (s, 1H), 11.64 (br s, 1H), 7.93 (s, 1H), 7.70 (s, 1H), 7.30-7.22 (m, 5H), 6.59 (d, J=6.9 Hz, 1H), 6.08 (s, 1H), 4.69 (br s, 2H), 4.19 (d, J=13 Hz, 2H), 3.51-3.46 (m, 4H), 3.08-2.84 (m, 4H), 2.76 (s, 3H).

Example 251 Adamantan-1-ylmethyl-[4-(3S)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]amine

MS (ESI): mass calcd. for C₂₁H₃₂N₄, 340.52 m/z found, 341.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.61 (d, J=7.5 Hz, 1H), 6.41 (dd, J=1.8 Hz, 7.5 Hz, 1H), 5.91 (d, J=1.5 Hz, 1H), 4.11-3.69 (m, 5H), 3.05 (s, 2H), 2.88 (s, 3H), 2.66-2.59 (m, 1H), 2.43-2.40 (m, 1H), 2.38 (s, 3H), 1.82 (dd, J=12 Hz, 27 Hz, 6H), 1.70 (s, 6H).

Example 252 4-(4-Methylpiperazin-1-yl)-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₀H₃₂N₄, 328.5 m/z found, 329.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.60 (d, J=7.8 Hz, 1H), 6.63 (dd, J=2.4 Hz, 7.8 Hz, 1H), 6.23 (d, J=2.1 Hz, 1H), 4.26 (d, J=14 Hz, 2H), 3.90 (dd, J=2.1 Hz, 11 Hz, 1H), 3.65 (d, J=12 Hz, 2H), 3.47 (t, J=13 Hz, 2H), 3.40-3.20 (m, 2H), 2.97 (s, 3H), 2.54-2.46 (m, 1H), 1.86-1.73 (m, 3H), 1.53-1.27 (m, 2H), 1.10-0.90 (m, 1H), 1.04 (s, 3H), 0.95 (s, 3H), 0.90 (s, 3H).

Example 253 N-(Bicyclo[2.21]hept-2-ylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₈H₂₈N₄, 300.45 m/z found, [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.61 (d, J=7.2 Hz, 1H), 6.41 (dd, J=7.2 Hz, 2.1 Hz, 1H), 5.83 (d, J=2.1 Hz, 1H), 4.09-4.06 (m, 1H), 3.97-3.91 (m, 1H), 3.75-3.66 (m, 3H), 3.36-3.18 (m, 2H), 2.86 (s, 3H), 2.64-2.57 (m, 1H), 2.40-2.21 (m, 3H), 1.92-1.90 (m, 1H), 1.63-1.23 (m, 7H), 0.85-0.79 (m, 1H).

Example 254 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-butylpyridin-2-amine

4-bromo-N-butylpyridin-2-amine. A solution of 4-bromo-2-fluoropyridine (2.0 g, 11.3 mmol) and n-butan-1-amine (752 mg, 10.3 mmol) in N-methyl-2-pyrrolidinone (NMP, 10 mL) was stirred at 100° C. for 1 hr. The reaction was allowed to cool to room temperature and diluted with DCM (50 mL), washed with water (10 mL*2).The organic layer was dried over Na₂SO₄, filtered and concentrated. The residue was purified by column chromatography (0-20% EtOAc-petrolumn ether gradient elution) to afford the desired product (1.4 g, 45%). ¹H NMR (300 MHz, CDCl₃): 7.88 (d, J=5.4 Hz, 1H), 6.70 (d, J=5.4 Hz, 1H), 6.54 (s, 1H), 4.60 (br s, 1H), 3.26-3.19 (m, 2H), 1.63-1.56 (m, 2H), 1.46-1.39 (m, 2H), 0.96 (t, J=7.2 Hz, 3H).

(R)-tert-butyl 1-(2-(butylamino)pyridin-4-yl)pyrrolidin-3-ylcarbamate. To a solution of 4-bromo-N-butylpyridin-2-amine (458 mg, 2 mmol), (R)-tert-butyl pyrrolidin-3-ylcarbamate (410 mg, 2.2 mmol) in anhydrous dioxane (12 mL) was added Pd₂(dba)₃ (200 mg, 0.22 mmol), 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (Xant-phos) (200 mg, 0.24 mmol) and t-BuONa (576 mg, 6 mmol) under atmosphere of argen. The resulting reaction was stirred at 100° C. for 2 hrs and diluted with water (40 mL), extracted with DCM. The combined organic layer was washed with brine, dried over Na₂SO₄, filtered and concentrated. The residue was purified by column chromatography (0-10% MeOH-DCM gradient elution) to afford the crude product (purity>70%).

(R)-4-(3-aminopyrrolidin-1-yl)-N-butylpyridin-2-amine dihydrochloride. Crude product obtained above was dissolved in MeOH (6 mL) and ether solution of HCl gas (ca. 4N, 10 mL) was added. The resulting reaction was stirred at ambient temperature for 20 hrs. The reaction was concentrated under reduced pressure and purified by prep-HPLC to afford the desired product (50 mg, 6.7% yield in two steps). ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.5 Hz, 1H), 6.39 (d, J=6.9 Hz, 1H), 5.79 (s, 1H), 4.89 (m, 1H), 4.15 (m, 1H), 3.74-3.66 (m, 3H), 3.38-3.29 (m, 2H), 2.60-2.53 (m, 1H), 2.34-2.30 (m, 1H), 1.73-1.64 (m, 2H), 1.56-1.46 (m, 2H), 1.02 (t, J=7.5 Hz, 3H); LC-MS: m/z=235.2 [M+H]⁺. t_(R)=0.92 min; HPLC: 100% (214 nm), 97% (254 nm), t_(R)=4.84 min.

The compounds in Example 255 through Example 297 were prepared using methods analogous to those described in Example 254.

Example 255 Adamantan-1-ylmethyl-[4-(4-methyl-piperazin-1-yl)-pyridin-2-yl]amine

MS (ESI): mass calcd. for C₂₁H₃₂N₄340.52 m/z found, 341.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.66 (d, J=7.2 Hz, 1H), 6.69 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.29 (d, J=2.1 Hz, 1H), 4.40-4.20 (m, 2H), 3.80-3.20 (m, 6H), 3.07 (s, 2H), 3.04 (s, 3H), 2.07 (s, 3H), 1.82 (dd, J=12 Hz, 27 Hz, 6H), 1.70 (s, 6H).

Example 256 N-(Cyclohexylmethyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₈N₄, 300.45 m/z found, 301.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.5 Hz, 1H), 6.37 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.78 (d, J=2.1 Hz, 1H), 4.55-4.45 (m, 1H), 3.95-3.78 (m, 3H), 3.51-3.37 (m, 4H), 3.12 (d, J=6.9 Hz, 2H), 2.41-2.33 (m, 1H), 2.20-2.00 (m, 1H), 1.87-1.64 (m, 6H), 1.40-1.02 (m, 5H).

Example 257 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(2-methylpropyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, 261.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.57 (d, J=7.5 Hz, 1H), 6.39 (d, J=7.2 Hz, 1H), 5.81 (s, 1H), 4.51-4.48 (m, 1H), 4.02-3.76 (m, 3H), 3.53-3.39 (m, 4H), 3.12 (d, J=6.9 Hz, 2H), 2.39-2.35 (m, 1H), 2.14-1.93 (m, 2H), 1.04 (d, J=6.6 Hz, 6H).

Example 258 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.84 (d, J=5.7 Hz, 1H), 8.60 (t, J=7.8 Hz, 1H). 8.11-7.99 (m, 2H), 7.69 (d, J=7.2 Hz, 1H), 6.46 (d, J=6.6 Hz, 1H), 5.90 (s, 1H), 5.09 (s, 2H), 4.09 (br, s, 1H), 3.85-3.34 (m, 4H), 2.58-2.45 (m, 1H), 2.28-2.22 (m, 1H).

Example 259 N-Cyclopentyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₂N₄, 246.36 m/z found, 247.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.21 (br, s, 1H), 10.06 (br, s, 2H), 8.10 (br, s, 1H), 7.80-7.60 (m, 1H), 6.08 (d, J=8.6 Hz, 1H), 5.59 (s, 1H), 5.20 (br, s, 1H), 4.32-3.95 (m, 7H), 2.53 (s, 3H), 1.71-1.59 (m, 8H).

Example 260 4-Piperazin-1-yl-N-(pyridin-2-ylmethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.85 (d, J=5.7 Hz, 1H), 6.63 (t, J=4.8 Hz, 1H), 8.12 (d, J=8.1 Hz, 1H), 8.04 (t, J=6.9 Hz, 1H), 7.74 (d, J=7.2 Hz, 1H), 6.77 (d, J=8.9 Hz, 1H), 6.32 (s, 1H), 5.15 (s, 2H), 3.91 (br, s, 4H), 3.36-3.30 (m, 4H).

Example 261 N-(Cyclopentylmethyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₆N₄, 286.42 m/z found, 287.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.57 (d, J=7.2 Hz, 1H), 6.39 (d, J=7.5 Hz, 1H), 5.81 (d, J=1.8 Hz, 1H), 4.52-4.48 (m, 1H), 4.01-3.76 (m, 3H), 3.52-3.37 (m, 4H), 3.21 (d, J=7.2 Hz, 2H), 2.42-2.35 (m, 1H), 2.26-2.08 (m, 2H), 1.92-1.60 (m, 6H), 1.35-1.29 (m, 2H).

Example 262 N-Cyclopentyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₄N₄, 272.4 m/z found, 273.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.28 (br s, 1H), 9.96 (br s, 1H), 9.68 (br s, 1H), 7.97 (d, J=6.9 Hz, 1H), 7.64-7.60 (m, 1H), 6.22 (d, J=6.9 Hz, 1H), 5.65 (s, 1H), 4.29-3.65 (m, 7H), 3.40-3.20 (m, 2H), 2.14-1.90 (m, 4H), 1.67-1.42 (m, 6H).

Example 263 4-[((3S)-3-Aminopyrrolidin-1-yl]-N-(4-fluorobenzyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₁₉FN₄, 288.36 m/z found, 287.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.54 (s, 1H), 7.40 (br s, 2H), 7.08-7.04 (m, 2H), 6.32 (s, 1H), 5.70 (s, 1H), 4.48 (s, 2H), 3.79 (br s, 1H), 3.90-3.40 (m, 4H), 2.47 (br s, 1H), 2.24 (br s, 1H).

Example 264 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₀N₄O, 236.32 m/z found, 237.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.57 (d, J=7.5 Hz, 1H), 6.36 (d, J=7.2 Hz, 1H), 5.81 (s, 1H), 4.12 (br, s, 1H), 3.89-3.84 (m, 1H), 3.70-3.59 (m, 5H), 3.52-3.50 (m, 2H), 3.47-3.34 (m, 5H), 2.56-2.52 (m, 1H), 2.30-2.26 (m, 1H).

Example 265 N-Bicyclo[2.2.1]hept-2-yl-4-(1,4-diazepan-1-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₁₆N₄, 286.42 m/z found, 287.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.64 (d, J=7.5 Hz, 1H), 6.62 (dd, J=7.5 Hz, 2.1 Hz, 1H), 5.98 (d, J=2.1 Hz, 1H), 4.04-3.98 (m, 2H), 3.78 (t, J=6.0 Hz, 2H), 3.52-3.49 (m, 2H), 3.42-3.36 (m, 3H), 2.41 (br s, 1H), 2.33-2.27 (m, 3H), 2.04-1.97 (m, 1H), 1.68-1.60 (m, 3H), 1.50-1.28 (m, 4H).

Example 266 Adamantan-2-yl-[4-(3aR,6aR)-(hexahydro-pyrrolo[3,4-b]pyrrol-5-yl)pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₁H₃₀N₄, 338.5 m/z found, 339.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.64 (d, J=7.5 Hz, 1H), 6.43 (dd, J=2.1 Hz, 7.2 Hz, 1H), 5.96 (s, 1H), 4.60-4.50 (m, 1H), 4.04-3.81 (m, 4H), 3.60-3.40 (m, 4H), 2.46-2.39 (m, 1H), 2.20-1.75 (m, 15H).

Example 267 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-benzylpyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₀N₄, 268.36 m/z found, 269.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.57 (d, J=6.3 Hz, 1H), 7.37-7.28 (m, 5H), 6.34 (d, J=6.0 Hz, 1H), 5.72 (s, 1H), 4.52 (s, 2H), 3.80 (br s, 1H), 3.90-3.40 (m, 4H), 2.48 (br s, 1H), 2.25 (br s, 1H).

Example 268 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyridin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₂N₄, 246.36 m/z found, 247.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.54 (d, J=7.2 Hz, 1H), 6.33 (d, J=6.9 Hz, 1H), 5.74 (s, 1H), 4.10-3.61 (m, 6H), 2.55-2.27 (m, 1H), 2.40-2.20 (m, 1H), 2.07-2.03 (m, 2H), 1.77-1.56 (m, 6H).

Example 269 4-Piperazin-1-yl-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridine-2-amine

MS (ESI): mass calcd. for C₁₉H₃₀N₄, 314.48 m/z found, 315.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.61 (d, J=7.5 Hz, 1H), 6.65 (d, J=7.5 Hz, 1H), 6.17 (d, J=1.8 Hz, 1H), 3.98-3.82 (m, 5H), 3.40-3.30 (m, 5H), 2.80-2.72 (m, 1H), 2.50-2.43 (m, 1H), 2.13-2.06 (m, 1H), 2.00-0.87 (m, 2H), 1.69-1.63 (m, 1H), 1.27 (s, 3H), 1.24-1.08 (m, 6H).

Example 270 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-bicyclo[2.2.1]hept-2-ylpyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₄N₄, 272.4 m/z found, 273.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.58 (d, J=7.5 Hz, 1H), 6.37 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.71 (d, J=2.1 Hz, 1H), 4.12-3.42 (m, 6H), 2.51-2.48 (m, 1H), 2.40-2.21 (m, 3H), 1.95-1.88 (m, 1H), 1.65-1.20 (m, 7H).

Example 271 N-[(1R)-1-Cyclohexylethyl]-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₉H₃₀N₄, 314.48 m/z found, 315.2 [M+H] ⁺. ¹H NMR (300 MHz, CD₃OD): 7.55 (d, J=7.5 Hz, 1H), 6.36 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.80 (d, J=2.4 Hz, 1H), 4.55-4.46 (m, 1H), 3.97-3.74 (m, 3H), 3.51-3.36 (m, 5H), 2.40-2.33 (m, 1H), 2.20-2.00 (m, 1H), 1.89-1.69 (m, 5H), 1.47-1.02 (m, 6H), 1.22 (d, J=6.3 Hz, 3H).

Example 272 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-[(1S,5R)-2.6.6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₉H₃₋N₄, 314.48 m/z found, 315.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=6.6 Hz, 1H), 6.35 (d, J=6.0 Hz, 1H), 5.79 (s, 1H), 4.10-3.62 (m, 6H), 2.76-2.70 (m, 1H), 2.47 (br s, 2H), 2.28 (br s, 1H), 2.08-1.62 (m, 4H), 1.26 (s, 3H), 1.20-1.00 (m, 1H), 1.16 (d, J=6.6 Hz, 3H), 1.07 (s, 3H).

Example 273 1-({4-[(3S)-3-Aminopyrrolidin-1-yl]pyridin-2-yl}amino)-2-methylpropan-2-ol

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.26 (s, 1H), 8.54 (br s, 3H), 7.62 (s, 2H), 6.22 (s, 1H), 5.79 (s, 1H), 3.93-3.40 (m, 5H), 3.18 (m, 2H), 2.29-2.15 (m, 2H), 1.14 (s, 6H).

Example 274 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclohexylpyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, 261.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.60 (d, J=7.2 Hz, 1H), 6.40 (d, J=7.2 Hz, 1H), 5.81 (s, 1H), 4.17-3.51 (m, 6H), 2.62-2.53 (m, 1H), 2.40-2.20 (m, 1H), 2.07-1.73 (m, 5H), 1.55-1.32 (m, 5H).

Example 275 N-(Cyclopentylmethyl)-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, 261.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.39 (br, s, 1H), 10.08 (br, s, 2H), 7.92 (br, s, 1H), 7.69-7.66 (m, 1H), 6.10 (d, J=6.6 Hz, 1H), 5.62 (s, 1H), 4.80 (br, s, 1H), 4.34-4.18 (m, 6H), 3.18-3.15 (m, 2H), 2.53 (s, 3H), 2.14-2.09 (m, 1H), 1.79-1.24 (m, 8H).

Example 276 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-phenylethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₂N₄, 282.39 m/z found, 283.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.35 (s, 1H), 8.55 (br s, 3H), 7.80 (s, 1H), 7.62 (m, 1H), 7.29-7.22 (m, 5H), 6.25 (d, J=6.0 Hz, 1H), 5.66 (s, 1H), 4.21-3.48 (m, 7H), 2.85 (m, 2H), 2.29-2.16 (m, 2H).

Example 277 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₄N₄O, 288.4 m/z found, 289.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.60 (d, J=7.5 Hz, 1H), 6.41 (dd, J=2.1 Hz, 7.5 Hz, 1H), 5.85 (d, J=1.8 Hz, 1H), 4.57-4.50 (m, 1H), 4.04-3.77 (m, 5H), 3.82-2.40 (m, 7H), 2.43-2.33 (m, 1H), 2.20-1.98 (m, 3H), 1.69-1.61 (m, 2H).

Example 278 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, 261.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.59 (d, J=7.5 Hz, 1H), 6.39 (dd, J=7.5 Hz, 1.8 Hz, 1H), 5.81 (d, J=1.5 Hz, 1H), 4.89 (m, 1H), 4.15 (m, 1H), 3.89-3.66 (m, 3H), 3.23 (d, J=7.5 Hz, 2H), 2.60-2.53 (m, 1H), 2.31-2.22 (m, 2H), 1.94-1.90 (m, 2H), 1.75-1.65 (m, 4H), 1.37-1.31 (m, 2H).

Example 279 1-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyridin-2-yl}amino)-2-methylpropan-2-ol

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.62 (d, J=7.2 Hz, 1H), 6.39 (d, J=7.2 Hz, 1H), 5.90 (s, 1H), 4.19 (m, 1H), 3.89 (m, 1H), 3.73-3.65 (m, 3H), 3.29 (s, 2H), 2.58-2.55 (m, 1H), 2.32-2.27 (m, 1H), 1.31 (s, 6H).

Example 280 N-tert-Butyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₃H₂₂N₄, 234.35 m/z found, 235.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.32 (br, s, 1H), 10.13 (br, s, 2H), 7.75-7.71 (m, 2H), 6.08 (d, J=5.7 Hz, 1H), 5.51-5.39 (m, 3H), 4.40-4.25 (m, 5H), 2.54 (s, 3H), 1.38 (s, 9H).

Example 281 N-Cyclopropyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₂H₁₈N₄, 218.3 m/z found, 219.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.36 (br, s, 1H), 10.21 (br, s, 2H), 8.33 (br, s, 1H), 7.69 (t, J=6.3 Hz, 1H), 6.15 (d, J=5.4 Hz, 1H), 5.63 (s, 1H), 4.54 (br, s, 4H), 4.34-4.15 (m, 5H), 2.53 (s, 3H), 0.85-0.84 (m, 2H), 0.54 (s, 2H).

Example 282 2-Methyl-1-({4-[3-(methylamino)azetidin-1-yl]pyridin-2-yl}amino)propan-2-ol

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.27 (br, s, 1H), 10.02 (br, s, 2H), 7.68-7.61 (m, 2H), 6.08 (d, J=6.6 Hz, 1H), 5.69 s, 1H), 4.33-4.20 (m, 7H), 3.17 (d, J=5.4 Hz, 2H), 2.54 (s, 3H), 1.16 (s, 6H).

Example 283 3-({4-[3-(Methylamino)azetidin-1-yl]pyridin-2-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₂H₂₀N₄O, 236.32 m/z found, 237.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.47 (br, s, 1H), 10.23 (br, s, 2H), 7.88 (br, s, 1H), 7.64 (t, J=6.6 Hz, 1H), 6.08 (d, J=6.6 Hz, 1H), 5.59 (s, 1H), 4.71 (br, s, 4H), 4.33-4.15 (m, 5H), 3.49 (t, J=6.3 Hz, 2H), 2.52 (s, 3H), 1.73-1.65 (m, 2H).

Example 284 4-[3-(Methylamino)azetidin-1-yl]-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₉H₃₀N₄, 314.48 m/z found, 315.3 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.27 (br, s, 1H), 9.97 (br, s, 2H), 8.06 (d, J=8.4 Hz, 1H), 7.65 (d, J=6.6 Hz, 1H), 6.05 (d, J=6.9 Hz, 1H), 5.61 (s, 1H), 4.34-4.15 (m, 7H), 4.15 (br, s, 1H), 2.70-2.63 (m, 1H), 2.55 (s, 3H), 2.37 (br, s, 1H), 2.05-1.94 (m, 2H), 1.84-1.81 (m, 1H), 1.53-1.48 (m, 1H), 1.09 (s, 3H), 1.06-0.94 (m, 6H).

Example 285 N-Benzyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₀N₄, 268.36 m/z found, 269.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.60 (br, s, 1H), 10.08 (br, s, 2H), 8.32-8.28 (m, 1H), 7.70-7.67 (m, 1H), 7.38-7.28 (m, 5H), 6.10 (d, J=7.2 Hz, 1H), 5.64 (s, 2H), 5.45 (br, s, 2H), 4.52 (d, J=5.7 Hz, 2H), 4.23-4.14 (m, 5H), 2.51 (s, 3H).

Example 286 N-(2-Methoxyethyl)-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₀N₄O, 236.32 m/z found, 237.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.43 (br, s, 1H), 10.15 (br, s, 2H), 7.78 (br, s, 1H), 7.65 (t, J=6.3 Hz, 1H), 6.10 (d, J=6.6 Hz, 1H), 5.64 (s, 1H), 4.36-4.14 (m, 9H), 3.48-3.42 (m, 4H), 3.3 (s, 3H), 2.53 (s, 3H).

Example 287 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₂₁H₃₂N₄, 340.52 m/z found, 341.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.56 (d, J=7.2 Hz, 1H), 6.38 (dd, J=7.5 Hz, J=2.1 Hz, 1H), 5.80 (d, J=1.8 Hz, 1H), 4.50-4.46 (m, 1H), 3.98-3.74 (m, 4H), 3.50-3.41 (m, 4H), 2.77-2.69 (m, 1H), 2.51-2.30 (m, 2H), 2.14-1.67 (m, 4H), 1.64-1.63 (m, 1H), 1.28 (s, 3H), 1.18-1.05 (m, 7H).

Example 288 N-tert-Butyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, 261.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.60 (d, J=7.5 Hz, 1H), 6.37 (d, J=7.2 Hz, 1H), 5.82 (s, 1H), 4.49 (t, J=6.8 Hz, 1H), 4.01-3.75 (m, 4H), 3.51-3.30 (m, 2H), 2.39-2.32 (m, 1H), 2.12-2.07 (m, 1H), 1.47 (s, 9H).

Example 289 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₂H₂₀N₄O, 236.32 m/z found, 237.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.52 (d, J=7.2 Hz, 1H), 6.30 (d, J=6.6 Hz, 1H), 5.74 (s, 1H), 4.06 (m, 1H), 3.79 (m, 1H), 3.57-3.54 (m, 5H), 3.43-3.39 (m, 2H), 3.34 (s, 3H), 2.49-2.44 (m, 1H), 2.21-2.19 (m, 1H).

Example 290 2-Methyl-1-[(4-piperazin-1-ylpyridin-2-yl)amino]propan-2-ol

MS (ESI): mass calcd. for C₁₃H₂₂N₄O, 250.35 m/z found, 251.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.63 (d, J=7.8 Hz, 1H), 6.64 (dd, J=7.8 Hz, J=2.4 Hz, 1H), 6.23 (d, J=1.8 Hz, 1H), 3.86-3.82 (m, 4H), 3.55 (s, 3H), 3.39-3.36 (m, 4H), 1.28 (s, 6H).

Example 291 N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3aR,6aR)-hexahydropyrrolo[3.4-b]pyrrol-5(1H)-yl]pyridin-2-amine

MB (ESI): mass calcd. for C₂₁H₃₂N₄, 340.52 m/z found, 341.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.50 (d, J=7.5 Hz, 1H), 6.31 (dd, J=2.1 Hz, 7.2 Hz, 1H), 5.71 (s, 1H), 4.43 (t, J=8.0 Hz, 1H), 3.93-3.68 (m, 3H), 3.45-3.20 (m, 6H), 2.44-2.25 (m, 3H), 2.06-1.90 (m, 6H), 1.57-1.52 (m, 1H), 1.52 (s, 3H), 1.19 (s, 3H), 0.93 (d, J=9.6 Hz, 1H).

Example 292 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyridin-2-amine

MS (ESI): mass calcd. for C₁₄H₂₂N₄, 246.36 m/z found, 247.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.25 (br, s, 1H), 8.57 (br, s, 3H), 7.95 (d, J=6.9 Hz, 1H), 7.64 (t, J=6.3 Hz, 1H), 6.27 (d, J=6.6 Hz, 1H), 5.68 (s, 1H), 4.04-3.87 (m, 3H), 3.66-3.40 (m, 4H), 2.38-2.18 (m, 2H), 2.02-1.96 (m, 2H), 1.70-1.24 (m, 6H).

Example 293 N-(2,2-Dimethylpropyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₂₆N₄, 274.41 m/z found, 275.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.57 (d, J=7.5 Hz, 1H), 6.38 (dd, J=2.4 Hz, 7.5 Hz, 1H), 5.90 (d, J=2.4 Hz, 1H), 4.51-4.48 (m, 1H), 4.00-3.75 (m, 3H), 3.52-3.37 (m, 4H), 3.11 (s, 2H), 2.40-2.34 (m, 1H), 2.12-2.08 (m, 1H), 1.03 (s, 9H).

Example 294 4-[3-(Methylamino)azetidin-1-yl]-N-(2-phenylethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₇H₂₂, N₄, 282.89 m/z found, 283.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.38 (br, s, 1H), 10.08 (br, s, 2H), 7.83-7.63 (m, 2H), 7.32-7.22 (m, 5H), 6.09 (d, J=8.9 Hz, 1H), 5.59 (s, 1H), 5.03 (br, s, 2H), 4.33-3.98 (m, 5H), 3.52-3.46 (m, 2H), 2.87 (t, J=7.2 Hz, 2H), 2.54 (s, 3H).

Example 295 N-(4-Fluorobenzyl)-4-[3-(methylamino)azeidin-1-yl]pyridin-2-amine

MS (ESI): mass calcd. for C₁₆H₁₉FN₄, 286.36 m/z found, 287.2 [M+H]⁺. ¹H NMR (300 MHz, DMSO-d₆): 12.55 (br, s, 1H), 9.99 (br, s, 2H), 8.28 (br, s, 1H), 7.68 (t, J=8.3 Hz, 1H), 7.45-7.41 (m, 2H), 7.24-7.18 (m, 2H), 8.11 (d, J=5.7 Hz, 1H), 5.63 (s, 1H), 4.51 (d, 5.7 Hz, 2H), 4.21-4.14 (m, 7H), 2.53 (s, 3H).

Example 296 Adamantan-1-yl-[4-(3aR,6aR)-(hexahydro-pyrrolo[3,4-b]pyrrol-5-yl)-pyridin-2-yl]-amine

MS (ESI): mass calcd. for C₂₁H₃₀N₄, 338.5 m/z found, 339.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.54 (d, J=7.2 Hz, 1H), 6.32 (d, J=7.5 Hz, 1H), 5.83 (s, 1H), 4.44 (t, J=6.6 Hz, 1H), 3.91-3.68 (m, 4H), 3.46-3.40 (m, 3H), 2.34-2.28 (m, 1H), 2.20-2.00 (m, 1H), 2.13 (s, 3H), 2.06 (s, 6H), 1.75 (s, 6H).

Example 297 4-[3-(Methylamino)azetidin-1-yl]-N-(pyridin-2-ylmethyl)pyridin-2-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.1 [M+H]^(+l .) ¹H NMR (300 MHz, CD₃OD): 8.76 (d, J=5.4 Hz, 1H), 8.55 (t, J=7.5 Hz, 1H), 8.03 (d, J=7.8 Hz, 1H), 7.96 (t, J=6.6 Hz, 1H), 7.59 (d, J=7.2 Hz, 1H), 6.18 (d, J=6.9 Hz, 1H), 5.74 (s, 1H), 5.01 (s, 2H), 4.41 (br, s, 2H), 4.25-4.21 (m, 3H), 2.65 (s, 3H).

Example 298 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyridazin-8-amine

3,4,5-trichloropyridazine. A solution of 4,5-dichloropyridazin-3(2H)-one (2 g, 12 mmol) in 20 mL of phosphoryl trichloride was heated to reflux for 2 hrs. The solvent was removed under reduce pressure. The residue was poured into water with stirring and extracted with dicloromathene (50 mL*3). The organic layer was washed with brine, dried over Na₂SO₄, evaporated to give the crude product (U.S. Pat. Appl. Publ. U.S. Pat. No. 6,800,758 (Egis Gyogyszergyar Rt., Hung., Oct. 5, 2004). The crude product was recrystallized with acetone/water to give the product (2 g, 83%). ¹H NMR (300 MHz, CDCl₃): 9.09 (s, 1H); LC-MS: m/z=182.9 [M+H]⁺.

(R)-tert-butyl 1-(5,6-dichloropyridazin-4-yl)pyrrolidin-3-ylcarbamate. To a stirred solution of 3,4,5-trichloropyridazine (500 mg, 5.5 mmol) and DIPEA (1 mL) in propan-2-ol (5 mL) was added (R)-tert-butyl pyrrolidin-3-ylcarbamate (508 mg, 5.5 mmol) at ambient temperature. The solvent was removed and the residue was purified by column chromatography (petroleum ether/ethyl acetate=2/1, v/v) to afford the title desired product (500 mg, 55%). ¹H NMR (300 MHz, CDCl₃): 8.42 (s, 1H), 5.06 (br s, 1H), 4.36 (br s, 1H), 4.05-3.99 (m, 1H), 3.90-3.66 (m, 3H), 2.28-2.23 (m, 1H), 2.09-2.07 (m, 1H), 1.48 (s, 9H): LC-MS: m/z=333.1 [M+H]⁺

(R)-tert-butyl 1-(5-chloro-6-(2-methoxyethylamino)pyridazin-4-yl) pyrrolidin-3-ylcarbamate. A mixture of 100 mg of (R)-tert-butyl 1-(5,6-dichloropyridazin-4-yl)pyrrolidin-3-ylcarbamate and 2-methoxyethanamine (1 mL) was heated at 145° C. for 40 min in microwave. The mixture was concentrated and the crude was purified by silica gel chromatography (EA/PE=1/4, v/v) to give the title product (50 mg, 45%). LC-MS: m/z=372.2 [M+H]⁺.

(R)-tert-butyl 1-(6-(2-methoxyethylamino)pyridazin-4-yl)pyrrolidin-3-ylcarbamate. To the mixture of (R)-tert-butyl 1-(5-chloro-6-(2-methoxyethylamino)pyridazin-4-yl) pyrrolidin-3-ylcarbamate (50 mg, 0.13 mmol) and ammonium formate (HCOONH₄) (85 mg, 1.3 mmol) in MeOH (2 mL) was added 10% Pd/C (20 mg). The resulting mixture was refluxed for 2 hours. The reaction was allowed to cool to room temperature and filtered. The filtrate was concentrated, diluted with EA (20 mL) and washed with brine (10 mL*2). The combined organic layer was dried over Na₂SO₄ and concentrated. The residue was purified by pre-TLC (PE/EA=1/5, v/v) to give the product as oil (20 mg, 44%). ¹H NMR (300 MHz, CDCl₃): 8.02 (s, 1H), 5.46 (s, 1H), 5.10-5.08 (m, 1H), 4.91 (br s, 1H), 4.33-4.26 (m, 1H), 3.59-3.51 (m, 4H), 3.40-3.35 (m, 4H), 3.19-3.15 (m, 1H), 2.28-2.19 (m, 1H), 1.99-1.97 (m, 1H), 1.44 (s, 9H); LC-MS: m/z=338.2 [M+H]⁺.

(R)-5-(3-aminopyrrolidin-1-yl)-N-(2-methoxyethyl)pyridazin-3-amine dihydrochloride. To solution of (R)-tert-butyl 1-(6-(2-methoxyethylamino)pyridazin-4-yl) pyrrolidin-3-ylcarbamate (198 mg, 0.59 mmol) in MeOH (3 mL) was added 7N HCl in ether (10 mL). The reaction was stirred at room temperature for 16 hours. The reaction was concentrated under reduced pressure to give the desired product as a light yellow solid (94.5 mg, 52%). ¹H NMR (300 MHz, CD₃OD): 8.14 (s, 1H), 6.12 (s, 1H), 4.15-3.54 (m, 9H), 3.40 (s, 3H), 2.57-2.52 (m, 1H), 2.32-2.30 (m, 1H): mass calcd. for C₁₁H₁₉N₅O, 237.31, LC-MS: m/z=238.2 [M+H]⁺. t_(R)=0.3 min; HPLC: 99% (214 nm), 95% (254 nm), t_(R)=4.4 min.

The compounds in Example 299 through Example 310 were prepared using methods analogous to those described in Example 298.

Example 299

5-[3-(Methylamino)azetidin-1-yl]-N-(4,4,4-trifluorobutyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₁₈F₃N₅, 289.31 m/z found, 290.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.84 (d, J=2.1 Hz, 1H), 5.88 (d, J=2.4 Hz, 1H), 4.60-4.40 (m, 2H), 4.31-4.22 (m, 3H), 3.31 (t, J=6.9 Hz, 2H), 2.69 (s, 3H), 2.26-2.18 (m, 2H), 1.86-1.79 (m, 2H).

Example 300 N⁵-(2-Aminoethyl)-N³-(2,2-dimethylpropyl)-N⁵-methylpyridazine-3,5-diamine

MS (ESI): mass calcd. for C₁₂H₂₃N₅, 237.35 m/z found, 238.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.19 (d, J=2.4 Hz, 1H), 8.29 (s, 1H), 3.79 (t, J=6.8 Hz, 2H), 3.21-3.08 (m, 7H), 0.94 (s, 9H).

Example 301 5-[3-(Methylamino)azetidin-1-yl]-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₈H₂₉N₅, 315.47 m/z found, 316.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.94 (s, 1H), 5.98 (s, 1H), 4.70-4.30 (m, 5H), 4.02-3.99 (m, 1H), 2.81 (s, 3H), 2.80-2.70 (m, 1H), 2.60-2.50 (m, 1H), 2.16-1.72 (m, 4H), 1.40-1.30 (m, 1H), 1.32 (s, 3H), 1.20 (d, J=7.2 Hz, 3H), 1.09 (s, 3H).

Example 302 N⁵-(2-Amino-ethyl)-N³-bicyclo[2.2.1]hept-2yl-N⁵-methylpyridazine-3,5-diamine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.19 (d, J=2.4 Hz, 1H), 6.08 (d, J=2.1 Hz, 1H), 3.77 (t, J=6.9 Hz, 2H), 3.44-3.42 (m, 1H), 3.14 (t, J=6.0 Hz, 2H), 3.09 (s, 3H), 2.24 (d, J=21 Hz, 2H), 1.88-1.81 (m, 1H), 1.58-1.14 (m, 7H).

Example 303 N⁵-(2-Aminoethyl)-N³-(cyclopentylmethyl)-N⁵-methylpyridazine-3,5-diamine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.36 m/z found, 250.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.19 (d, J=2.4 Hz, 1H), 6.15 (s, 1H), 3.78 (t, J=6.9 Hz, 2H), 3.21-3.10 (m, 7H), 1.81-1.53 (m, 7H), 1.25-1.20 (m, 2H).

Example 304 5-[(3S)-3-Aminopyrrolidin-1-yl]-N-(bicyclo[2.2.1]hept-2-ylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₅N₅, 287.41 m/z found, 283.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.18 (d, J=2.1 Hz, 1H), 6.12 (d, J=2.1 Hz, 1H), 4.20-3.50 (m, 5H), 3.40-3.00 (m, 2H), 2.64-2.57 (m, 1H), 2.40-2.20 (m, 3H), 1.96-0.82 (m, 9H).

Example 305 3-({5-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridazin-3-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₁N₅O, 263.35 m/z found, 264.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.11 (s, 1H), 6.08 (s, 1H), 4.52-4.48 (m, 1H), 4.05-3.84 (m, 2H), 3.76-3.66 (m, 2H), 3.56-3.41 (m, 5H), 2.39-2.33 (m, 1H), 2.11-2.09 (m, 1H), 1.92-1.83 (m, 2H).

Example 306 5-(3-Aminoazetidin-1-yl)-N-{[(1S,2S,5S)-6,6-dimethylbicyclo[3.1.1]hept-2-yl]methyl}pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₇N₅, 301.44 m/z found, 302.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.79 (d, J=2.7 Hz, 1H), 5.78 (s, 1H), 4.60-4.40 (m, 2H), 4.30-4.10 (m, 3H), 3.30-3.10 (m, 2H), 2.4O-2.20 (m, 2H), 1.94-1.85 (m, 5H), 1.50-1.40 (m, 1H), 1.14 (s, 3H), 0.99 (s, 3H), 0.88 (d, J=9.9 Hz, 1H).

Example 307 5-(1,4-Diazepan-1-y1)-N-(2,2-dimethylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.39 m/z found, 264.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.36 (d, J=2.1 Hz, 1H), 6.41 (d, J=2.1 Hz, 1H), 4.04-4.03 (m, 2H), 3.81-3.79 (m, 2H), 3.53-3.49 (m, 2H), 3.43-3.41 (m, 2H), 3.20 (s, 2H), 2.30-2.28 (m, 2H), 1.06 (s, 9H).

Example 308 N-Bicyclo[2.2.1]hept-2-yl-5-(1,4-diazepan-1-yl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 287.41 m/z found, 288.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.35 (s, 1H), 6.22 (s, 1H), 4.03-4.02 (m, 2H), 3.79-3.77 (m, 2H), 3.55-3.49 (m, 3H), 3.42-3.37 (m, 3H), 2.32-2.28 (m, 3H), 1.99-1.92 (m, 1H), 1.70-1.62 (m, 3H), 1.59-1.22 (m, 4H).

Example 309 N-Cyclopropyl-5-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₁₉N₅, 245.33 m/z found, 246.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.17 (d, J=2.4 Hz, 1H), 6.07 (d, J=2.1 Hz, 1H), 4.53-4.49 (m, 1H), 3.99-3.40 (m, 7H), 2.67-2.62 (m, 1H), 2.41-2.37 (m, 1H), 2.14-2.08 (m, 1H), 1.01-0.95 (m, 2H), 0.71-0.66 (m, 2H).

Example 310 N-Butyl-5-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.13 (d, J=2.4 Hz, 1H), 6.06 (d, J=2.1 Hz, 1H), 4.54-4.50 (m, 1H), 4.08-3.40 (m, 7H), 3.33-3.31 (m, 2H), 2.41-2.34 (m, 1H), 2.14-2.09 (m, 1H), 1.73-1.63 (m, 2H), 1.51-1.44 (m, 2H), 1.00 (t, J=7.5 Hz, 3H).

Example 311 N-(Cyclopentylmethyl)-4-piperazin-1-ylpyridin-2-amine

The titled compound was prepared in a manner analogous to Example 254. MS (ESI): mass calcd. for C₁₅H₂₄N₄, 260.39 m/z found, 261.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.55 (d, J=7.5 Hz, 1H), 6.59 (dd, J=7.5 Hz, J=1.8 Hz, 1H), 6.09 (d, J=1.8 Hz, 1H), 3.79 (t, J=5.7 Hz, 4H), 3.33 (t, J=5.1 Hz, 4H), 3.17 (d, J=7.5 Hz, 2H), 2.20-2.15 (m, 1H), 1.87-1.81 (m, 2H), 1.66-1.58 (m, 4H), 1.29-1.23 (m, 2H).

The compounds in Example 312 through Example 371 were prepared using methods analogous to those described in Example 298.

Example 312 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(bicyclo[2.2.1]hept-2-ylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₅N₅, 287.41 m/z found, 288.3 [M+H] ⁺. ¹H NMR (300 MHz, CD₃OD): 8.18 (d, J=2.1 Hz, 1H), 6.10 (d, J=2.1 Hz, 1H), 4.20-3.50 (m, 5H), 3.40-3.00 (m, 2H), 2.64-2.57 (m, 1H), 2.40-2.20 (m, 3H), 2.00-0.82 (m, 9H).

Example 313 3-({5-[(3R)-3-Aminopyrrolidin-1-yl]pyridazin-3-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (br s, 1H), 6.06 (s, 1H), 4.14 (s, 1H), 3.84-3.54 (m, 6H), 3.45-3.41 (m, 2H), 2.55-2.51 (m, 1H), 2.28 (br, s, 1H), 1.88 (t, J=6.6 Hz, 2H).

Example 314 3-[(5-Piperazin-1-ylpyridazin-3-yl)amino]propan-1-ol

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.37 (s, 1H), 6.42 (br, s, 1H), 3.89 (br, s, 4H), 3.69 (t, J=5.4 Hz, 2H), 3.47-3.47 (m, 6H), 1.89 (t, J=6.3 Hz, 2H).

Example 315 N-Cyclopropyl-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₁H₁₇N₅, 219.29 m/z found, 220.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.38 (s, 1H), 6.37 (s, 1H), 3.87-3.85 (m, 4H), 3.37-3.36 (m, 4H), 2.62-2.60 (br, s, 1H), 0.97-0.91 (m, 2H), 0.65 (br, s, 2H).

Example 318 N-(Cyclopentylmethyl)-5-(1,4-diazepan-1-yl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.36 (d, J=2.4 Hz, 1H), 6.39 (d, J=2.4 Hz, 1H), 4.04-4.02 (m, 2H), 3.80-3.78 (m, 2H), 3.52-3.49 (m, 2H), 3.42-3.37 (m, 2H), 3.28 (d, J=7.5 Hz, 2H), 2.30-2.22 (m, 3H), 1.93-1.91 (m, 2H), 1.73-1.65 (m, 4H), 1.34-1.32 (m, 2H).

Example 317 5-[(3S)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (s, 1H), 6.08 (s, 1H), 4.17-4.15 (m, 1H), 4.10-3.54 (m, 4H), 3.27 (d, J=7.2 Hz, 2H), 2.60-2.51 (m, 1H), 2.29-2.20 (m, 2H), 1.92-1.90 (m, 2H), 1.73-1.65 (m, 4H), 1.36-1.32 (m, 2H).

Example 318 5-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(2-methylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.07 (d, J=2.4 Hz, 1H), 6.04 (d, J=2.1 Hz, 1H), 4.48-4.44 (m, 1H), 4.06-3.77 (m, 3H), 3.53-3.26 (m, 4H), 3.10 (d, J=7.2 Hz, 2H), 2.36-2.29 (m, 1H), 2.09-0.97 (m, 2H), 0.98 (b, J=6.9 Hz, 6H).

Example 319 6-[3-(Methylamino)azetidin-1-yl]-N-(2-methylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.94 (d, J=2.1 Hz, 1H), 5.98 (s, 1H), 4.70-4.34 (m, 5H), 3.17 (d, J=7.2 Hz, 2H), 2.81 (s, 3H), 1.99-1.93 (m, 1H), 1.05 (d, J=6.6 Hz, 6H).

Example 320 N-(2-Methoxyethyl)-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.94 (d, J=2.4 Hz, 1H), 6.04 (s, 1H), 4.70-4.35 (m, 5H), 3.65-3.62 (m, 2H), 3.56-3.53 (m, 2H), 3.42 (s, 3H), 2.81 (s, 3H).

Example 321 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1R)-1-phenylethyl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.09 (s, 1H), 7.39-7.29 (m, 5H), 5.95 (s, 1H), 4.10 (br, s, 1H), 3.98-3.53 (m, 5H), 2.54-2.48 (m, 1H), 2.26-2.22 (m, 1H), 1.61 (d, J=6.9 Hz, 3H).

Example 322 5-(3-Aminoazetidin-1-yl)-N-bicyclo[2.2.1]hept-2-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₁N₅, 259.36 m/z found, 260.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.89 (d, J=1.5 Hz, 1H), 5.87 (s, 1H), 4.59 (br s, 2H), 4.33 (br, s, 3H), 3.50-3.48 (m, 1H), 2.35-2.27 (m, 2H), 1.94-1.87 (m, 1H), 1.67-1.18 (m, 4H).

Example 323 5-(3-Aminoazetidin-1-yl)-N-(2,2-dimethylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.90 (s, 1H), 6.06 (s, 1H), 4.62 (br s, 2H), 4.35 (br s, 3H), 3.15 (s, 2H), 1.08 (s, 9H).

Example 324 N-(2,2-Dimethylpropyl)-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.36 m/z found, 250.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.95 (d, J=2.4 Hz, 1H), 6.10 (d, J=2.1 Hz, 1H), 4.70-4.36 (m, 5H), 3.19 (s, 2H), 2.33 (s, 3H), 1.07 (s, 9H).

Example 325 N-Cyclohexyl-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.84 (s, 1H), 5.86 (s, 1H), 4.53 (br, s, 2H), 4.30-4.26 (m, 3H), 3.57-3.49 (m, 1H), 2.73 (d, J=3.3 Hz, 3H), 1.96-1.92 (m, 2H), 1.79-1.63 (m, 3H), 1.44-1.11 (m, 5H).

Example 326 5-(3-Aminoazetidin-1-yl)-N-cyclopentylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.88 (s, 1H), 5.86 (s, 1H), 4.58 (br s, 2H), 4.40-4.20 (m, 3H), 4.00-3.96 (m, 1H), 2.09-2.04 (m, 2H), 1.80-1.58 (m, 6H).

Example 327 N-(Cyclopropylmethyl)-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.87 (d, J=2.4 Hz, 1H), 5.91 (d, J=2.4 Hz, 1H), 4.56 (br, s, 2H), 4.36-4.26 (m, 3H), 3.16 (d, J=7.2 Hz, 2H), 1.15-1.01 (m, 1H), 0.66-0.60 (m, 2H), 0.34-0.29 (m, 2H).

Example 328 5-(3-Aminoazetidin-1-yl)-N-(2-methylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₁H₁₉N₅, 221.31 m/z found, 222.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.90 (s, 1H), 5.94 (s, 1H), 4.70-4.30 (m, 5H), 3.13 (d, J=6.9 Hz, 2H), 1.93-1.92 (m, 1H), 1.02 (d, J=6.3 Hz, 6H).

Example 329 5-(3-Aminoazetidin-1-yl)-N-benzylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₁₇N₅, 255.33 m/z found, 256.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.88 (d, J=2.4 Hz, 2H), 7.38-7.29 (m, 5H), 5.90 (d, J=2.4 Hz, 1H), 4.53 (s, 4H), 4.35-4.30 (m, 3H).

Example 330 N-Benzyl-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.80 (br, s, 1H), 7.27 (br, s, 5H), 5.82 (s, 1H), 4.44 (s, 4H), 4.19 (br, 3H), 2.68 (s, 3H).

Example 331 N-Bicyclo[2.2.1]hept-2-yl-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.38 m/z found, 274.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.88 (s, 1H), 5.82 (d, J=2.7 Hz, 1H), 4.58 (br, s, 2H), 4.35-4.23 (m, 3H), 3.48-3.46 (m, 1H), 2.36 (s, 3H), 2.28-2.27 (m, 2H), 1.94-1.87 (m, 1H), 1.63-1.17 (m, 7H).

Example 332 N-Cyclopentyl-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.35 m/z found, 248.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.78 (br, s, 1H), 5.77 (br, s, 1H), 4.46 (br, s, 2H), 4.25-4.21 (m, 3H), 3.88-3.86 (m, 1H), 2.67 (s, 3H), 1.99-1.95 (m, 2H), 1.70-1.48 (m, 6H).

Example 333 5-(3-Aminoazetidin-1-yl)-N-cyclopropylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₀H₁₅N₅, 205.26 m/z found, 206.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.95 (d, J=2.4 Hz, 1H), 5.92 (d, J=1.8 Hz, 1H), 4.60 (br, s, 2H), 4.37-4.31 (m, 3H), 2.64-2.59 (m, 1H), 0.99-0.93 (m, 2H), 0.69-0.64 (m, 2H).

Example 334 3-({5-[3-(Methylamino)azetidin-1-yl]pyridazin-3-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.90 (d, J=2.7 Hz, 1H), 5.97 (d, J=2.4 Hz, 1H), 4.58 (br, s, 2H), 4.39-4.31 (m, 3H), 3.68 (t, J=6.0 Hz, 2H), 3.42 (t, J=6.9 Hz, 2H), 2.77 (s, 3H), 1.91-1.82 (m, 2H).

Example 335 5-(3-Aminoazetidin-1-yl)-N-(2-methoxyethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₀H₁₇N₅O, 223.28 m/z found, 224.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.94 (d, J=2.4 Hz, 1H), 6.01 (d, J=2.7 Hz, 1H), 4.64 (br s, 2H), 4.41-4.36 (m, 3H), 3.66-3.63 (m, 2H), 3.56-3.53 (m, 2H), 3.42 (s, 3H).

Example 336 5-[(3S)-3-Aminopyrrolidin-1-yl]-N-cyclopropylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₁H₁₇N₅, 219.29 m/z found, 220.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.16 (d, J=2.4 Hz, 1H), 6.04 (d, J=2.1 Hz, 1H), 4.13-3.53 (m, 5H), 2.67-2.51 (m, 2H), 2.31-2.24 (m, 1H), 1.00-0.94 (m, 2H), 0.70-0.65 (m, 2H).

Example 337 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₁₈N₆, 270.34 m/z found, 271.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.80 (d, J=5.7 Hz, 1H), 8.53 (t, J=7.8 Hz, 1H), 8.20 (s, 1H), 8.05-7.93 (m, 2H), 6.24 (s, 1H), 5.01 (s, 2H), 4.09 (br, s, 1H), 3.82-3.60 (m, 4H), 2.53-2.46 (m, 1H), 2.24-2.22 (m, 1H).

Example 338 3-({5-[(3S)-3-Aminopyrrolidin-1-yl]pyridazin-3-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₁H₁₉N₅O, 237.31 m/z found, 238.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (d, J=2.1 Hz, 1H), 6.05 (d, J=2.4 Hz, 1H), 4.13-3.53 (m, 7H), 3.43 (t, J=6.9 Hz, 2H), 2.58-2.48 (m, 1H), 2.30-2.26 (m, 1H), 1.92-1.84 (m, 2H).

Example 339 5-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.13 (s, 1H), 6.05 (s, 1H), 4.14-3.16 (m, 5H), 3.15 (d, J=6.9 Hz, 2H), 2.58-2.52 (m, 1H), 2.28-2.20 (m, 1H), 2.00-1.91 (m, 1H), 0.93 (d, J=6.9 Hz, 6H).

Example 340 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-benzylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.09 (s, 1H), 7.35-7.29 (m, 5H), 5.98 (s, 1H), 4.52 (s, 2H), 4.07 (br, s, 1H), 3.78-3.41 (m, 4H), 2.52-2.45 (m, 1H), 2.24-2.20 (m, 1H).

Example 341 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-methoxybenzyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅O, 299.38 m/z found, 300.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.16 (s, 1H), 7.34 (d, J=8.7 Hz, 2H), 6.96 (d, J=8.7 Hz, 2H), 6.03 (d, J=2.1 Hz, 1H), 4.50 (s, 2H), 4.14-3.56 (m, 5H), 3.81 (s, 3H), 2.59-2.52 (m, 1H), 2.31-2.27 (m, 1H).

Example 342 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-fluorobenzyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₁₈FN₅, 287.34 m/z found, 288.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.19 (d, J=2.1 Hz, 1H), 7.50-7.45 (m, 2H), 7.20-7.14 (m, 2H), 6.08 (d, J=2.1 Hz, 1H), 4.59 (s, 2H), 4.17-3.58 (m, 5H), 2.61-2.52 (m, 1H), 2.36-2.30 (m, 1H).

Example 343 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-methylbenzyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. H NMR (300 MHz, CD₃OD): 8.17 (d, J=2.7 Hz, 1H), 7.33 (d, J=8.1 Hz, 2H), 7.25 (d, J=7.8 Hz, 2H), 6.08 (d, J=2.4 Hz, 1H), 4.56 (s, 2H), 4.17-3.58 (m, 5H), 2.63-2.51 (m, 1H), 2.40 (s, 3H), 2.37-2.26 (m, 1H).

Example 344 N-(4-Methylbenzyl)-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.29 (d, J=2.4 Hz, 1H), 7.18 (d, J=8.1 Hz, 2H), 7.11 (d, J=8.1 Hz, 2H), 6.29 (d, J=2.4 Hz, 1H), 4.42 (s, 2H), 3.80-3.76 (m, 4H), 3.32-3.29 (m, 4H), 2.24 (s, 3H).

Example 345 N-Cyclopentyl-5-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₃N₅, 273.38 m/z found, 274.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.13 (s, 1H), 6.06 (br s, 1H), 4.52 (m, 1H), 4.06-3.40 (m, 8H), 2.39-2.35 (m, 1H), 2.10-1.80 (m, 3H), 1.82-1.62 (m, 6H).

Example 346 N-(4-Fluorobenzyl)-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₁₈FN₅, 287.34 m/z found, 288.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.41 (d, J=2.4 Hz, 1H). 7.46-7.42 (m, 2H), 7.17-7.12 (m, 2H), 6.42 (d, J=2.4 Hz, 1H), 4.57 (s, 2H), 3.92-3.88 (m, 4H), 3.43-3.40 (m, 4H)

Example 347 N-(4-Methoxybenzyl)-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅O, 299.38 m/z found, 300.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.39 (s, 1H), 7.33 (d, J=7.2 Hz, 2H), 6.95 (d, J=7.2 Hz, 2H), 6.38 (s, 1H), 4.49 (s, 2H), 3.87 (m, 4H), 3.79 (s, 3H), 3.42-3.39 (m, 4H).

Example 348 N-Benzyl-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₁₉N₅, 269.35 m/z found, 270.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.41 (d, J=2.7 Hz, 1H), 7.42-7.35 (m, 5H), 6.41 (d, J=2.7 Hz, 1H), 4.58 (s, 2H), 3.95-3.87 (m, 4H), 3.43-3.36 (m, 4H).

Example 349 N-[(1R)-1-Phenylethyl]-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.36 (s, 1H), 7.41-7.31 (m, 5H), 6.37 (s, 1H), 4.95-4.84 (m, 1H), 3.85 (m, 4H), 3.41-3.38 (m, 4H), 1.63 (d, J=6.9 Hz, 3H).

Example 350 3-({5-[(3R)-3-Aminopyrrolidin-1-yl]pyridazin-3-yl}amino)-2,2-dimethylpropan-1-ol

MS (ESI): mass calcd. for C₁H₂₃N₅O, 265.36 m/z found, 2.80.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (s, 1H), 6.21 (s, 1H), 4.32-3.58 (m, 5H), 3.39 (s, 2H), 3.28 (s, 2H), 2.62-2.52 (m, 1H), 2.32-2.30 (m, 1H), 1.03 (s, 6H).

Example 351 N-Cyclopropyl-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₁H₁₇N₅, 219.29 m/z found, 220.2 [M+H]^(+l .) ¹H NMR (300 MHz, CD₃OD): 7.95 (d, J=2.1 Hz, 1H), 5.94 (s, 1H), 4.58 (br, s, 2H), 4.39-4.31 (m, 3H), 2.77 (s, 3H), 2.64-2.60 (m, 1H), 0.99-0.93 (m, 2H), 0.69-0.67 (m, 2H).

Example 352 5-[3-(Methylamino)azetidin-1-yl]-N-(pyridin-2-ylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₁₈N₆, 270.34 m/z found, 271.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.82 (d, J=4.8 Hz, 1H), 8.60 (s, 1H), 8.08-7.99 (m, 3H), 6.20 (s, 1H), 5.07 (br, s, 2H), 4.59-4.43 (m, 4H), 4.25 (br, s, 1H), 2.73 (d, J=10.2 Hz, 3H).

Example 353 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (s, 1H), 6.05 (s, 1H), 4.13-3.59 (m, 5H), 3.15 (d, J=6.9 Hz, 2H), 2.58-2.51 (m, 1H), 2.40-2.20 (m, 1H), 1.99-1.91 (m, 1H), 1.03 (d, J=6.6 Hz, 6H).

Example 354 N-Cyclopentyl-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₁, N₅, 247.35 m/z found, 248.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.32 (d, J=2.4 Hz, 1H), 6.34 (d, J=2.1 Hz, 1H), 4.02-3.94 (m, 1H), 3.88-3.83 (m, 4H), 3.39-3.35 (m, 4H), 2.08-1.99 (m, 2H), 1.79-1.55 (m, 6H).

Example 355 N-Cyclohexyl-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.33 (d, J=2.7 Hz, 1H), 6.31 (d, J=2.7 Hz, 1H), 3.84 (t, J=5.1 Hz, 4H), 3.55 (br, 1H), 3.40 (t, J=5.1 Hz, 4H), 2.01-1.80 (m, 4H), 1.62-1.75 (m, 1H), 1.48-1.28 (m, 5H).

Example 356 N-Butyl-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.36 (s, 1H), 6.37 (s, 1H), 3.88 (t, J=5.4 Hz, 4H), 3.41 (t, J=5.4 Hz, 4H), 3.35-3.29 (m, 2H), 1.69-1.64 (m, 2H), 1.50-1.43 (m, 2H), 0.99 (t, J=7.5 Hz, 3H).

Example 357 N-(2,2-Dimethylpropyl)-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.36 m/z found, 250.2 [M+H]⁺. ¹H NMR (300 MHz, CO₃OD): 8.36 (d, J=2.7 Hz, 1H), 6.52 (d, J=2.4 Hz, 1H), 3.88 (t, J=5.1 Hz, 4H), 3.41 (t, J=5.1 Hz, 4H), 3.17 (s, 2H), 1.03 (s, 9H).

Example 358 5-(3-Aminoazetidin-1yl)-N-(cyclopentylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.35 m/z found, 248.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.77 (s, 1H), 5.80 (d, J=2.1 Hz, 1H), 4.48 (br s, 2H), 4.26-4.20 (m, 3H), 3.12 (d, J=7.2 Hz, 2H), 2.16-2.05 (m, 1H), 1.78-1.52 (m, 6H), 1.22-1.16 (m, 2H).

Example 359 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.00 (s, 1H), 5.91 (d, J=24 Hz, 1H), 4.03-4.00 (m, 1H), 3.90-3.40 (m, 4H), 3.13 (d, J=7.5 Hz, 2H), 2.47-2.40 (m, 1H), 2.23-2.07 (m, 2H), 1.81-1.52 (m, 6H), 1.23-1.17 (m, 2H).

Example 360 N-(Cyclopentylmethyl)-5-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 287.41 m/z found, 288.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.00 (s, 1H), 5.92 (s, 1H), 4.41-4.38 (m, 1H), 3.91-3.70 (m, 3H), 3.44-3.27 (m, 4H), 3.13 (d, J=7.5 Hz, 2H), 2.31-2.23 (m, 1H), 2.14-2.01 (m, 2H), 1.79-1.52 (m, 6H), 1.23-1.17 (m, 2H).

Example 361 N-(Cyclopropylmethyl)-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.36 (s, 1H), 6.40 (s, 1H), 3.89 (t, J=7.8 Hz, 4H), 3.41 (t, J=4.8 Hz, 4H), 3.20 (d, J=6.9 Hz, 2H), 1.17-1.15 (m, 1H), 0.64 (d, J=8.1 Hz, 2H), 0.34 (d, J=4.8 Hz, 2H).

Example 362 N-(2-Phenylethyl)-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.33 (d, J=2.1 Hz, 1H), 7.30-7.22 (m, 5H), 6.29 (d, J=2.1 Hz, 1H), 3.86 (t, J=5.4 Hz, 4H), 3.63 (t, J=6.9 Hz, 2H), 3.41-3.34 (m, 4H), 2.98 (t, J=6.9 Hz, 2H).

Example 363 N-(Cyclopentylmethyl)-5-piperazin-1-ylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.33 (s, 1H), 6.38 (s, 1H), 3.86 (s, 4H), 3.50-3.23 (s, 6H), 2.24-2.17 (m, 1H), 1.86 (br, s, 2H), 1.65 (br, s, 4H), 1.29 (br, s, 2H).

Example 364 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-phenylethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.09 (s, 1H), 7.29-7.23 (m, 5H), 5.96 (s, 1H), 4.13-3.64 (m, 5H), 3.62 (t, J=6.6 Hz, 2H), 2.98 (t, J=6.6 Hz, 2H), 2.53 (m, 1H), 2.28 (m, 1H).

Example 365 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclohexylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.11 (s, 1H), 6.03 (s, 1H), 4.14-3.56 (m, 8H), 2.58-2.51 (m, 1H), 2.40-2.20 (m, 1H), 1.85-1.68 (m, 5H), 1.54-1.28 (m, 5H).

Example 366 2,2-Dimethyl-3-[(5-piperazin-1-ylpyridazin-3-yl)amino]propan-1-ol

MS (ESI): mass calcd. for C₁₃H₂₃N₅O, 265.38 m/z found, 266.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.27 (d, J=1.2 Hz, 1H), 6.46 (d, J=2.4 Hz, 1H), 3.81-3.79 (m, 4H), 3.33-3.32 (m, 4H), 3.26 (s, 2H), 3.16 (s, 2H), 1.02 (s, 6H).

Example 367 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-butylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅, 235.33 m/z found, 236.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.02 (s, 1H), 5.92 (d, J=2.1 Hz, 1H), 4.04-3.44 (m, 5H), 3.24-3.20 (m, 2H), 2.48-2.41 (m, 1H), 2.21-2.14 (m, 1H), 1.62-1.52 (m, 2H), 1.41-1.31 (m, 2H), 0.90 (t, J=7.2 Hz, 3H).

Example 368 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₁N₅, 247.35 m/z found, 248.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.13 (s, 1H), 6.04 (s, 1H), 4.15-3.36 (m, 6H), 2.56-2.52 (m, 1H), 2.31 (m, 1H), 2.09 (br s, 2H), 1.80-1.62 (m, 8H).

Example 369 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclopropylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (br, s, 1H), 6.04 (br, s, 1H), 4.14 (br, s, 1H), 3.92-3.73 (m, 4H), 3.19 (d, J=6.6 Hz, 2H), 2.58-2.51 (m, 1H), 2.29-2.27 (m, 1H), 1.15 (br, s, 1H), 0.68-0.64 (m, 2H), 0.35-0.34 (m, 2H).

Example 370 N-(Cyclopentylmethyl)-5-[3-(methylamino)azetidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 7.89 (d, J=2.1 Hz, 1H), 5.95 (d, J=2.1 Hz, 1H), 4.82-4.57 (m, 2H), 4.40-4.30 (m, 3H), 3.34-3.32 (m, 2H), 2.77 (s, 3H), 2.23-2.18 (m, 1H), 1.88-1.86 (m, 2H), 1.66-1.64 (m, 4H), 1.30-1.28 (m, 2H).

Example 371 5-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2,2-dimethylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.36 m/z found, 250.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (s, 1H), 6.15 (s, 1H), 4.13-3.50 (m, 5H), 3.15 (s, 2H), 2.57-2.50 (m, 1H), 2.40-2.20 (m, 1H), 1.02 (s, 9H).

Example 372 5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-phenylethyl)pyridazin-3-amine

3,4,5-trichloropyridazine. A solution of 4,5-dichloropyridazin-3(2H)-one (2 g, 12 mmol) in 20 mL of phosphoryl trichloride was heated to reflux for 2 hrs. The solvent was removed under reduce pressure. The residue was poured into water with stirring and extracted with dicloromathene (50 mL*3). The organic layer was washed with brine, dried over Na₂SO₄, evaporated to give the crude product. The crude product was recrystallized with acetone/water to give the product (2 g, 89%). ¹H NMR (300 MHz, CDCl₃): 9.09 (s, 1H); LC-MS: m/z=182.9 [M+H]⁺.

(R)-tert-butyl 1-(5,6-dichloropyridazin-4-yl)pyrrolidin-3-ylcarbamate. To a stirred solution of 3,4,5-trichloropyridazine (500 mg, 2.7 mmol) and DIPEA (1 mL) in propan-2-ol (5 mL) was added (R)-tert-butyl pyrrolidin-3-ylcarbamate (508 mg, 2.7 mmol) at ambient temperature (18 h). The solvent was removed and the residue was purified by column chromatography (Petroleum Ether/Ethyl Acetate=2/1, v/v) to afford the title desired product (500 mg, 55%).

¹H NMR (300 MHz, CDCl₃): 8.42 (s, 1H), 5.06 (br s, 1H), 4.36 (br s, 1H), 4.05-3.99 (m, 1H), 3.90-3.66 (m, 3H), 2.28-2.23 (m, 1H), 2.09-2.07 (m, 1H), 1.48 (s, 9H): LC-MS: m/z=333.1 [M+H]⁺

(R)-tert-butyl 1-(5,6-dichloropyridazin-4-yl)pyrrolidin-3-yl(methyl)-carbamate. NaH (60% in oil, 0.72 g, 18.0 mmol) was suspended in 40 mL of anhydrous DMF. A solution of (R)-tert-butyl 1-(5,6-dichloropyridazin-4-yl)pyrrolidin-3-ylcarbamate (5 g, 15 mmol) in anhydrous DMF (40 mL) was added at −5° C. After 40 min, CH₃I (2.55 g, 18 mmol) was added. Then the resulting mixture was stirred at ambient temperature for 2 hours. The reaction was monitored by LC-MS. Water (100 mL) was added and the mixture was extracted with EtOAc (3×200 mL). The organic layer was washed with brine (3×200 mL), dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by silica gel (Petroleum Ether/EtOAc=5/1, v/v) to afford the desired product (4.2 g, 80%). ¹H NMR (300 MHz, CDCl₃) δ 8.39 (s, 1H), 4.77-4.76 (m, 1H), 3.86-3.62 (m, 4H), 2.85 (s, 3H), 2.18-2.11 (m, 2H), 1.46 (s, 9H); LS-MS: m/z=347.1 [M+H]⁺.

(R)-tert-butyl1-(5-chloro-6-(phenethylamino)pyridazin-4-yl)pyrrolidin-3-yl(methyl)-carbamate. A mixture of (R)-tert-butyl 1-(5,6-dichloropyridazin-4-yl)pyrrolidin-3-yl(methyl) carbamate (400 mg, 1.15 mmol) and 2-phenylethanamine (1 mL) was stirred at 150° C. for 40 min in microwave. The mixture was concentrated and the residue was purified by silica gel chromatography (MeOH/DCM=150, v/v) to afford the desired product (295 mg, 59%). LC-MS: m/z=432.1 [M+H]⁺.

(R)-tert-butylmethyl(1-(6-(phenethylamino)pyridazin-4-yl)pyrrolidin-3-yl) carbamate. To a mixture of (R)-tert-butyl1-(5-chloro-6-(phenethylamino)pyridazin-4-yl)pyrrolidin-3-yl(methyl)-carbamate (295 mg, 0.68 mmol) and HCOONH₄ (0.5 g, 7.9 mmol) in MeOH (15 mL) was added 10% Pd/C (0.3 g) and the resulting mixture was refluxed 30 min. The reaction was allowed to cool and filtered. The filtrate was concentrated, then diluted with EA (20 mL) and washed with brine (10 mL*2 ). The combined organic layer was dried over Na₂SO₄, filtered, concentrated and purified by prep-HPLC to give the product as oil (177 mg, 65%). ¹H NMR (300 MHz, CDCl₃): δ 8.80 (s, 1H), 7.70 (d, J=5.4 Hz 1H), 7.30-7.18 (m, 5H), 5.30 (5.30, J=9.6 Hz, 1H), 4.86 (d, J=6.3 Hz, 1H), 3.78-3.73 (m, 1H), 3.49-3.35 (m, 4H), 2.96 (t, J=7.2 Hz, 2H), 2.82 (s, 3H), 2.23 (s, 2H), 1.48 (s, 9H): LC-MS: m/z=398.1 [M+H]⁺.

(R)-5-(3-(methylamino)pyrrolidin-1-yl)-N-phenethylpyridazin-3-amine dihydrochloride. To a solution of (R)-tert-butylmethyl(1-(6-(phenethylamino)pyridazin-4-yl) pyrrolidin-3-yl)carbamate (177 mg, 44 mmol) in MeOH (3 mL) was added ether solution of HCl gas (7N, 10 mL). The reaction was stirred at room temperature for 16 hours. The solution was concentrated under reduced pressure to give the desired product as a white solid (32.2 mg, 20%). ¹H NMR (300 MHz, CD₃OD): 8.13 (d, J=2.4 Hz, 1H), 7.33-7.25 (m, 5H), 5.98 (d, J=2.4 Hz, 1H), 4.01-3.62 (m, 7H), 3.00 (t, J=6.9 Hz, 2H), 2.84 (s, 3H), 2.60-2.30 (m, 2H); LC-MS: m/z=298.3 [M+H]⁺. t_(R)=1.0 min; HPLC: 98% (214 nm), 99% (254 nm), t_(R)=7.1 min.

The compounds in Example 373 through Example 403 were prepared using methods analogous to those described in Example 372.

Example 373 N-[(1R)-1-Cyclohexylethyl]-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₉N₅, 303.45 m/z found, 304.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.11 (s, 1H), 6.04 (s, 1H), 4.05-3.56 (m, 6H), 2.82 (s, 3H), 2.59-2.54 (m, 1H), 2.40-2.30 (m, 1H), 1.90-1.70 (m, 5H), 1.60-1.00 (m, 9H).

Example 374 N-(Bicyclo[2.2.1]hept-2-ylmethyl)-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₇N₅, 301.44 m/z found, 302.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.18 (d, J=2.1 Hz, 1H), 6.13 (d, J=2.1 Hz, 1H), 4.20-3.50 (m, 5H), 3.40-3.10 (m, 2H), 2.88 (s, 3H), 2.67-2.62 (m, 1H), 2.50-2.20 (m, 3H), 2.00-0.82 (m, 9H).

Example 375 N-(Bicyclo[2.2.1]hept-2-ylmethyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₇N₅, 301.44 m/z found, 302.3 [M+H]^(+l .) ¹H NMR (300 MHz, CD₃OD): 8.19 (d, J=2.4 Hz, 1H), 6.13 (d, J=2.4 Hz, 1H), 4.20-3.50 (m, 5H), 3.40-3.10 (m, 2H), 2.88 (s, 3H), 2.65-2.60 (m, 1H), 2.50-2.20 (m, 3H), 2.00-0.82 (m, 9H).

Example 376 N-(2-Methoxyethyl)-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.18 (s, 1H), 6.14 (s, 1H), 4.10-3.57 (m, 9H), 3.44 (s, 3H), 2.87 (s, 3H), 2.70-2.30 (m, 2H).

Example 377 N-Cyclopropyl-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.13 (s, 1H), 6.01 (s, 1H), 4.01-3.73 (m, 5H), 2.78 (s, 3H), 2.57-2.50 (m, 2H), 2.31-2.29 (m, 1H), 0.94-0.92 (m, 2H), 0.64 (s, 2H).

Example 378 N-[(1R)-1-Cyclohexylethyl]-5-[(3R)-3-(methylamino)pyrrolidin-1yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₉N₅, 303.45 m/z found, 304.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (s, 1H), 6.05 (s, 1H), 4.10-3.50 (m, 6H), 2.82 (s, 3H), 2.70-2.50 (m, 1H), 2.40-2.30 (m, 1H), 1.88-1.69 (m, 5H), 1.60-1.03 (m, 9H).

Example 379 5-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₃N₅, 249.36 m/z found, 250.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.14 (s, 1H), 6.05 (s, 1H), 4.05-3.60 (m, 5H), 3.15 (d, J=6.9 Hz, 2H), 2.83 (s, 3H), 2.59-2.55 (m, 1H), 2.35-2.30 (m, 1H), 1.98-1.93 (m, 1H), 1.03 (d, J=6.6 Hz, 6H).

Example 380 N-Cyclopentyl-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.16 (s, 1H), 6.06 (s, 1H), 4.06-3.60 (m, 6H), 2.86 (s, 3H), 2.60 (m, 1H), 2.41 (m, 1H), 2.14-1.33 (m, 8H).

Example 381 N-Bicyclo[2.2.1]hept-2-yl-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 287.41 m/z found, 288.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.18 (d, J=2.4 Hz, 1H), 6.04 (d, J=2.1 Hz, 1H), 4.11-3.39 (m, 6H), 2.87 (s, 3H), 2.66-2.59 (m, 1H), 2.42-2.35 (m, 3H), 2.02-1.95 (m, 1H), 1.70-1.24 (m, 7H).

Example 382 N-(Cyclopentylmethyl)-6-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.02 (d, J=1.8 Hz, 1H), 5.97 (s, 1H), 3.96-3.44 (m, 5H), 3.25 (s, 2H), 3.15 (d, J=7.2 Hz, 2H), 2.67 (s, 3H), 2.51-2.44 (m, 1H), 2.30-2.26 (m, 1H), 2.15-2.08 (m, 1H), 1.84-1.78 (m, 2H), 1.60-1.52 (m, 4H), 1.24-1.18 (m, 2H).

Example 383 2,2-Dimethyl-3-({5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₄H₂₅N₅O, 279.39 m/z found, 266.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.16 (s, 1H), 6.21 (s, 1H), 4.09-3.58 (m, 5H), 3.39 (s, 2H), 3.28 (s, 2H), 2.81 (s, 3H), 2.82-2.58 (m, 1H), 2.39-2.37 (m, 1H), 1.03 (s, 6H).

Example 384 5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(4-methylbenzyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.16 (s, 1H), 7.30 (d, J=7.2 Hz, 2H), 7.22 (d, J=7.2 Hz, 2H), 6.06 (s, 1H), 4.53 (s, 2H), 4.15-3.50 (m, 5H), 2.83 (s, 3H), 2.81-2.55 (m, 1H), 2.40-2.30 (m, 1H), 2.35 (s, 3H).

Example 385 N-(2,2-Dimethylpropyl)-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.39 m/z found, 264.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (d, J=1.8 Hz, 1H), 6.15 (s, 1H), 4.08-3.81 (m, 5H), 3.15 (s, 2H), 2.81 (s, 3H), 2.59-2.57 (m, 1H), 2.39-2.36 (m, 1H), 1.03 (s, 9H).

Example 386 5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(4,4,4-trifluorobutyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₀F₃N₅, 303.33 m/z found, 304.1 [M+H]⁺. CD₃OD: 8.05 (s, 1H), 6.00 (s, 1H), 4.10-3.50 (m, 5H), 3.34 (t, J=6.6 Hz, 2H), 2.73 (s, 3H), 2.60-2.40 (m, 1H), 2.40-2.20 (m, 3H), 1.90-1.80 (m, 2H).

Example 387 N-(Furan-3-ylmethyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₁₉N₅O, 273.34 m/z found, 274.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.16 (s, 1H), 7.62 (s, 1H), 7.53 (s, 1H), 6.49 (s, 1H), 6.08 (s, 1H), 4.42 (s, 2H), 4.10-3.40 (m, 5H), 2.81 (s, 3H), 2.70-2.50 (m, 1H), 2.40-2.20 (m, 1H).

Example 388 N-[(6,6-Dimethylbicyclo[3.1.1]hept-2-yl)methyl]-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₉H₃₁N₅, 329.49 m/z found, 330.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (d, J=2.1 Hz, 1H), 6.06 (s, 1H), 4.08-3.80 (m, 5H), 2.79 (s, 3H), 2.83-2.56 (m, 1H), 2.47-2.35 (m, 4H), 2.08-1.98 (m, 7H, contain paraffin), 1.61-1.56 (m, 1H), 1.27 (s, 3H), 1.12 (s, 3H), 1.06-1.00 (m, 1H).

Example 389 5-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(4,4,4-trifluorobutyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₃H₂₀F₃N₅, 303.33 m/z found, 304.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.18 (d, J=1.8 Hz, 1H), 6.08 (s, 1H), 4.08-3.56 (m, 5H), 3.45 (t, J=7.2 Hz, 2H), 2.80 (s, 3H), 2.64-2.57 (m, 1H), 2.40-2.31 (m, 3H, 2.00-1.90 (m, 2H).

Example 390 3-({5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]pyridazin-3-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺.¹H NMR (300 MHz, CD₃OD): 8.08 (s, 1H), 8.02 (s, 1H), 4.01-3.63 (m, 7H), 3.42 (t, J=6.6 Hz, 2H), 2.78 (s, 3H), 2.57-2.50 (m, 1H), 2.30 (br, s, 1H), 1.88-1.80 (m, 2H).

Example 391 N-(Cyclohexylmethyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₇N₅, 289.43 m/z found, 290.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (s, 1H), 6.05 (s, 1H), 4.10-3.40 (m, 5H), 3.18 (d, J=6.9 Hz, 2H), 2.82 (s, 3H), 2.70-2.50 (m, 1H), 2.40-2.30 (m, 1H), 1.90-1.60 (m, 6H), 1.40-1.00 (m, 5H).

Example 392 N-(2,2-Dimethylpropyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.39 m/z found, 264.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.14 (s, 1H), 6.18 (s, 1H), 4.07-3.50 (m, 5H), 3.17 (s, 2H), 2.83 (s, 3H), 2.58 (m, 1H), 2.38 (m, 1H), 1.04 (s, 9H).

Example 393 N-(2-Methoxyethyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.13 (s, 1H), 6.11 (s, 1H), 4.06-3.54 (m, 9H), 3.39 (s, 3H), 2.82 (s, 3H), 2.58 (m, 1H), 2.40 (m, 1H).

Example 394 N-[(6,6-Dimethylbicyclo[3.1.1]hept-2-yl)methyl]-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₉H₃₁N₅, 329.49 m/z found, 330.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (s, 1H), 6.06 (s, 1H), 4.08-3.58 (m, 5H), 2.84 (s, 3H), 2.63-2.37 (m, 4H), 2.16-1.98 (m, 6H), 1.66-1.59 (m, 1H), 1.37-1.32 (m, 1H), 1.27 (s, 3H), 1.12 (s, 3H), 1.06-1.00 (m, 1H).

Example 395 N-Cyclopropyl-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₁₉N₅, 233.32 m/z found, 234.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.17 (d, J=2.7 Hz, 1H), 6.05 (d, J=1.8 Hz, 1H), 4.07-3.60 (m, 5H), 2.82 (s, 3H), 2.66-2.54 (m, 2H), 2.39-2.34 (m, 1H), 1.00-0.94 (m, 2H), 0.70-0.65 (m, 2H).

Example 396 N-(Cyclohexylmethyl)-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₇N₅, 289.43 m/z found, 290.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (s, 1H), 6.05 (s, 1H), 4.10-3.40 (m, 5H), 3.16 (d, J=6.9 Hz, 2H), 2.82 (s, 3H), 2.70-2.50 (m, 1H), 2.40-2.30 (m, 1H), 1.90-1.60 (m, 6H), 1.40-1.00 (m, 5H).

Example 397 N-Benzyl-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.19 (d, J=2.1 Hz, 1H), 7.45-7.37 (m, 5H), 6.12 (s, 1H), 4.62 (s, 2H), 4.09-3.52 (m, 5H), 2.86 (s, 3H), 2.82-2.58 (m, 1H), 2.44-2.40 (m, 1H).

Example 398 N-(4-Fluorobenzyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₀FN₅, 301.37 m/z found, 302.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.05 (s, 1H), 7.36-7.32 (m, 2H), 7.05-7.00 (m, 2H), 5.96 (s, 1H), 4.46 (s, 2H), 3.95-3.40 (m, 5H), 2.71 (s, 3H), 2.48-2.43 (m, 1H), 2.40-2.20 (m, 1H).

Example 399 N-(4-Fluorobenzyl)-5-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₀FN₅, 301.37 m/z found, 302.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.17 (s, 1H), 7.46-7.42 (m, 2H), 7.18-7.12 (m, 2H), 6.06 (s, 1H), 4.56 (s, 2H), 4.15-3.47 (m, 5H), 2.82 (s, 3H), 2.82-2.55 (m, 1H), 2.42-2.34 (m, 1H).

Example 400 N-(4-Methoxybenzyl)-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅O, 313.41 m/z found, 314.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.16 (d, J=2.1 Hz, 1H), 7.34 (d, J=3.7 Hz, 2H), 6.06 (d, J=8.7 Hz, 2H), 6.06 (s, 1H), 4.50 (s, 2H), 4.13-3.56 (m, 5H), 3.83 (s, 3H), 2.83 (s, 3H), 2.62-2.55 (m, 1H), 2.39-2.35 (m, 1H).

Example 401 5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R)-1-phenylethyl]pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.1 [M+H]⁺. CD₃OD: 8.12 (d, J=2.4 Hz, 1H), 7.49-7.31 (m, 5H), 6.01 (s, 1H), 4.04-3.36 (m, 6H), 2.82 (s, 3H), 2.58-2.53 (m, 1H), 2.37-2.33 (m, 1H), 1.63 (d, J=6.6 Hz, 3H).

Example 402 5-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₀N₆, 284.37 m/z found, 285.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.79 (d, J=5.1 Hz, 1H), 8.39 (t, J=7.8 Hz, 1H), 8.25 (d, J=2.1 Hz, 1H), 7.94-7.82 (m, 2H), 6.27 (br, s, 1H), 5.01 (s, 2H), 4.07-3.60 (m, 7H), 2.84 (s, 3H), 2.61-2.56 (m, 1H), 2.38-2.36 (m, 1H).

Example 403 3-({5-[(3S)-3-(Methylamino)pyrrolidin-1-yl]pyridazin-3-yl}amino)propan-1-ol

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.12 (d, J=2.1 Hz, 1H), 6.05 (d, J=2.1 Hz, 1H), 4.07-3.67 (m, 7H), 3.44 (t, J=6.9 Hz, 2H), 2.77 (s, 3H), 2.61-2.54 (m, 1H), 2.38-2.31 (m, 1H), 1.92-1.84 (m, 2H).

Example 404 N-(2,2-Dimethylpropyl)-5-(4-methylpiperazin-1-yl)pyridazin-3-amine

5-iodopyridazin-3(2H)-one. A mixture of 4,5-dichloropyridazin-3(2R)-one (25 g, 0.152 mol) in 250 mL of hydrogen iodide acid (57 w %) was heated to reflux for 18 hrs. The solution was cooled to ambient temperature and filtered. The precipitate was washed with saturated sodium thiosulfate solution. The precipitate was dried to give the desired product as a yellow solid (Int. Pat. Appl. Publ. WO 2008/013838 (Cephalon Inc., Jan. 31, 2008)) (15 g, 45%). ¹H NMR (300 MHz, CDCl₃): 13.26 (br s, 1H), 8.08 (s, 1H), 7.54 (s, 1H); LC-MS: m/z=222.9 [M+H]⁺.

5-(4-methylpiperazin-1-yl)pyridazin-3(2H)-one. A solution of 5-iodopyridazin-3(2H)-one (0.1 g, 0.45 mmol) and 1-methylpiperazine (0.09 g, 0.9 mmol) in ethanol (10 mL) was heated to reflux for 18 hrs. The solvent was removed under reduce pressure to give a crude oil. The crude oil was purified by silica gel chromatography (DCM/MeOH=30/1, v/v) to give yellow solid (60 mg, 68%). ¹H NMR (300 MHz, DMSO-d₆): 12.20 (br s, 1H), 7.92 (s, 1H), 5.72 (s, 1H), 3.33-3.29 (m, 4H), 2.38-2.35 (s, 4H), 2.19 (s, 3H); LC-MS: m/z=195.0 [M+H]⁺.

3-chloro-5-(4-methylpiperazin-1-yl)pyridazine. A solution of 5-(4-methylpiperazin-1-yl)pyridazin-3(2H)-one (5.82 g, 0.03 mol) in 25 mL of phosphoryl trichloride was heated to 80° C. for 3 hrs. The solution was concentrated and diluted with NaOH solution (0.5N) and pH was adjusted to 10. The solution was extracted with DCM (3×150 mL), washed with brine (3×100 mL), dried over Na₂SO₄, concentrated to give the crude oil. The residue was purified by silica gel chromatography (DCM/MeOH=40/1, v/v) to give colorless solid (1.4 g, 22%). ¹H NMR (300 MHz, CDCl₃): 8.75 (s, 1H), 6.68 (s, 1H), 3.47-3.44 (m, 4H), 2.57 (s, 4H), 2.38 (s, 3H); LC-MS: m/z=213.1 [M+H]⁺.

5-(4-methylpiperazin-1-yl)-N-neopentylpyridazin-3-amine diformic acid. A solution of 3-chloro-5-(4-methylpiperazin-1-yl)pyridazine (212 mg, 1 mmol) in 1 mL of 2,2-dimethylpropan-1-amine was stirred at 200° C. in microwave for 20 min. The solution was concentrated and purified by silica gel chromatography to give the crude solid which was further purified by prep-HPLC to give the title product (160 mg, 43%). ¹H NMR (300 MHz, CDCl₃): 14.44 (s, 1H), 9.34 (s, 1H), 8.40 (s, 2H), 7.91 (s, 1H), 5.90 (s, 1H), 3.50 (s, 4H), 2.90 (s, 2H), 2.57 (s, 4H), 2.29 (s, 3H), 0.88 (s, 9H): LC-MS: m/z=264.1 [M+H]⁺.

5-(4-methylpiperazin-1-yl)-N-neopentylpyridazin-3-amine dihydro chloride. A solution of hydrogen chloride in ether (7N, 20 mL) was added into a solution of 5-(4-methylpiperazin-1-yl)-N-neopentylpyridazin-3-amine diformic acid in MeOH (3 mL). The mixture was stirred at ambient temperature for 18 hrs. The solvent was removed by reduce pressure to give the title product (160 mg, 100%). ¹H NMR (300 MHz, CD₃OD): 8.41 (s, 1H), 6.58 (s, 1H), 4.40-4.35 (m, 2H), 4.00-3.40 (m, 6H), 3.22 (s, 2H), 3.02 (s, 3H), 1.08 (s, 9H); LC-MS: m/z=264.1 [M+H]⁺. MS (ESI): mass calcd. for C₁₄H₂₅N₅, 263.39 m/z found, 264.1 [M+H]⁺.

The compounds Example 405 through Example 411 were prepared using methods analogous to those described in Example 404.

Example 405 N-(2-Methoxyethyl)-5-(4-methylpiperazin-1-yl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₂H₂₁N₅O, 251.33 m/z found, 252.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.38 (s, 1H), 6.46 (s, 1H), 4.35 (br s, 2H), 3.90-3.20 (m, 10H), 3.40 (s, 3H), 2.99 (s, 3H)

Example 406 N-Bicyclo[2.2.1]hept-2-yl-5-(4-methylpiperazin-1-yl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₅N₅, 287.41 m/z found, 288.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.37 (d, J=2.4 Hz, 1H), 6.34 (d, J=2.7 Hz, 1H), 4.28 (br, s, 2H), 3.63-3.51 (m, 6H), 2.98 (m, 3H), 2.37-1.97 (m, 2H), 1.97-1.90 (m, 1H), 1.62-1.19 (m, 8H).

Example 407 N-Cyclopentyl-5-(4-methylpiperazin-1-yl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.41 (s, 1H), 6.41 (s, 1H), 4.33-3.57 (m, 9H), 3.02 (s, 3H), 2.13 (br s, 2H), 1.83-1.69 (m, 6H).

Example 408 N-(Cyclopentylmethyl)-5-(4-methylpiperazin-1-yl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₅N₅, 275.4 m/z found, 276.1 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.35 (d, J=3.0 Hz, 1H), 6.40 (d, J=2.4 Hz, 1H), 4.91-3.23 (m, 10H), 2.97 (s, 3H), 2.27-2.17 (m, 1H), 1.90-1.82 (m, 2H), 1.72-1.59 (m, 4H), 1.58-1.26 (m, 2H).

Example 409 5-(4-Methylpiperazin-1-yl)-N-(2-phenylethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₇H₂₃N₅, 297.41 m/z found, 298.2 [M+H]⁺. ¹H NMR (300 MHz, D₂O): 8.04 (s, 1H), 7.27-7.18 (m, 5H), 5.89 (s, 1H), 4.02 (br s, 2H), 3.58-3.54 (m, 4H), 3.32 (br s, 2H), 3.11 (br s, 2H), 2.87 (s, 3H), 2.85 (m, 2H).

Example 410 N-Benzyl-5-(4-methylpiperazin-1-yl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₆H₂₁N₅, 283.38 m/z found, 284.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.41 (d, J=1.2 Hz, 1H), 7.41-7.31 (m, 5H), 6.48 (s, 1H), 4.60 (s, 2H), 4.35 (br s, 4H), 3.60 (br s, 4H), 2.98 (s, 3H).

Example 411 5-(4-Methylpiperazin-1-yl)-N-(pyridin-2-ylmethyl)pyridazin-3-amine

MS (ESI): mass calcd. for C₁₅H₂₀N₆, 284.37 m/z found, 285.3 ¹H NMR (300 MHz, CD₃OD): 8.77 (d, J=5.4 Hz, 1H), 8.47-8.42 (m, 2H), 7.97-7.85 (m, 2H), 6.63 (s, 1H), 5.03 (s, 2H), 4.38 (br, 2H), 3.59-3.26 (m, 6H), 2.94 (s, 3H), (trace of ether).

Example 412 N-cyclopentyl-5-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridazin-3-amine

The titled compound was prepared in a manner analogous to Example 101. MS (ESI): mass calcd. for C₁₄H₂₃N₅, 261.37 m/z found, 262.2 [M+H]⁺. ¹H NMR (400 MHz, D₂O) d 8.01 (d, J=2.5, 1H), 5.90 (d, J=2.4, 1H), 4.12-4.05 (m, 1H), 4.03-3.92 (m, 2H), 3.91-3.67 (m, 3H), 2.80 (s, 3H), 2.64-2.50 (m, 1H), 2.38-2.29 (m, J=5.7, 1H), 2.09-1.95 (m, J=6.6, 2H), 1.79-1.54 (m, 7H).

Example 413 (R)-5-(3-(methylamino)pyrrolidin-1-yl)-N-(1-adamantyl)pyridazin-3-amine dihydrochloride

(R)-tert-butyl 1-(6-chloropyridazin-4-yl)pyrrolidin-3-ylcarbamate. A solution of 3,5-dichloropyridazine (4.47 g, 30 mmol), (R)-tert-butyl pyrrolidin-3-ylcarbamate (5.59 g, 30 mmol) and triethylamine (8.1 g, 80 mmol) in THF (50 mL) was stirred at ambient temperature for 20 hrs. The solvent was removed under reduced pressure and the residue was purified by column chromatography to afford the desired product (5.4 g, 60%) as a colorless solid. LC-MS: m/z=299.2 [M+H⁺]⁺.

(R)-tert-butyl-1-(6-chloropyridazin-4-yl)pyrrolidin-3-yl(methyl) carbamate. A solution of (R)-tert-butyl 1-(6-chloropyridazin-4-yl)pyrrolidin-3-ylcarbamate (3.6 g, 12.05 mmol) in N,N-dimethylformamide (DMF, 40 mL) was added into a suspension of 60% sodium hydride (0.58 g, 14.5 mmol) in DMF (40 mL) at 0° C. The mixture was stirred at 0° C. for further 30 min then Iodomethane (2.06 g, 14.5 mmol) was added into the mixture and the resulting reaction was stirred for further 3 h at ambient temperature. Water (100 mL) was added and the mixture was extracted with dichloromethane. The combined organic layer was dried over Na₂SO₄, filtered and concentrated. The solvent was removed under reduced pressure and the residue was purified by column chromatography to afford the desired product (2.5 g, 66%) as a brown solid. ¹H NMR (300 MHz, CDCl₃): 8.47 (d, J=2.4 Hz, 1H), 6.41 (d, J=2.4 Hz, 1H), 4.89 (br s, 1H), 3.58-3.52 (m, 2H), 3.42-3.86 (m, 1H), 3.29-3.23 (m, 1H), 2.82 (s, 3H), 2.27-2.14 (m, 2H), 1.47 (s, 9H).

(R)-tert-butyl methyl(1-(6-(1-adamentylamino)pyridazin-4-yl)pyrrolidin-3-yl)carbamate. A mixture of (R)-tert-butyl 1-(6-chloropyridazin-4-yl)pyrrolidin-3-yl(methyl) carbamate (78 mg, 0.25 mmol), 1-adamantylamine (76 mg, 0.5 mmol), BINAP (10.9 mg, 0.0175 mmol), palladium acetate (3.9 mg, 0.0175 mmol) and t-BuONa (72.1 mg, 0.75 mmol) in 1,2-dimethoxyethane (2 mL) was charged with N₂. The reaction mixture was stirred at 80° C. for 1.5 hours. The solution was diluted with ethyl acetate (5 mL) and washed with 5% NaHCO₃ solution. The solvent was removed under reduced pressure and the residue was purified by column chromatography 0-3.5% NH₃ MeOH/DCM to afford the desired product (64 mg, 60%) as a colorless solid. LC-MS: m/z=428.3 [M+H]⁺.

(R)-5-(3-(methylamino)pyrrolidin-1-yl)-N-(1-adamantyl)pyridazin-3-amine dihydrochloride. (R)-tert-butyl methyl(1-(6-(1-adamantylamino)pyridazin-4-yl)pyrrolidin-3-yl)carbamate (120 mg, 0.28 mmol) was dissolved in MeOH (4 mL) and 7N HCl/Et₂O solution (20 mL) was added. The resulting solution was stirred at ambient temperature for 18 hrs. The solvent was concentrated to give the desired product as a light yellow solid (73 mg, 60%). MS (ESI): mass calcd. for C₁₉H₂₉N₅, 327.48 m/z found, 328.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (s, 1H), 6.12 (s, 1H), 4.08-3.60 (m, 5H), 2.84 (s, 3H), 2.61-2.56 (m, 1H), 2.42-2.38 (m, 1H), 2.20 (s, 3H), 2.10 (s, 6H), 1.87-1.77 (m, 6H).

The compounds in Examples 414 through 416 were made analogously to Example 413.

Example 414 (R)-5-(3-(methylamino)pyrrolidin-1-yl)-N-(2-adamantyl)pyridazin-3-amine dihydrochloride

MS (ESI): mass calcd. for C₁₉H₂₉N₅, 327.48 m/z found, 328.3 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (d, J=2.4 Hz, 1H), 6.26 (s, 1H), 4.08-3.60 (m, 6H), 2.84 (s, 3H), 2.60-2.56 (m, 1H), 2.42-2.37 (m, 1H), 2.11-1.85 (m, 12H), 1.76-1.71 (m, 2H).

Example 415 (S)-5-(3-(methylamino)pyrrolidin-1-yl)-N-(2-adamantyl)pyridazin-3-amine dihydrochloride

MS (ESI): mass calcd. for C₁₉H₂₉N₅, 327.48 m/z found, 328.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (d, J=2.1 Hz, 1H), 6.26 (s, 1H), 4.91-3.61 (m, 6H), 2.84 (s, 3H), 2.63-2.56 (m, 1H), 2.42-2.37 (m, 1H), 2.11-1.85 (m, 12H), 1.75-1.71 (m, 2H).

Example 416 (S)-5-(3-(methylamino)pyrrolidin-1-yl)-N-(1-adamantyl)pyridazin-3-amine dihydrochloride

MS (ESI): mass calcd. for C₁₉H₂₉N₅, 327.48 m/z found, 328.2 [M+H]⁺. ¹H NMR (300 MHz, CD₃OD): 8.15 (s, 1H), 6.12 (s, 1H), 4.08-3.60 (m, 5H), 2.84 (s, 3H), 2.61-2.56 (m, 1H), 2.42-2.38 (m, 1H), 2.38 (s, 3H), 2.10 (s, 6H), 1.87-1.77 (m, 6H).

Binding Assay on Recombinant Human Histamine H₄Receptor

Cell pellets from SK-N-MC cells stably or transiently transfected with human H₄ receptor (NCBI accession No. AF312230) were used for the binding assays. Cell pellets were homogenized in 50 mM Tris/5 mM EDTA buffer and supernatants from an 800 g spin were collected and recentrifuged at 30,000 g for 30 min. Pellets were rehomogenized in 50 mM Tris/5 mM EDTA buffer. For competition binding studies, cell membranes were incubated with 2× K_(p) (10 nM),[³H] histamine (Specific activity: 14.2 to 23 C_(i)/mmol), with or without test compounds for 45 to 60 min at 4 to 25° C. K_(i) values were calculated based on an experimentally determined appropriate K_(D) values according to Cheng and Prusoff (Biochem. Pharmacol. 1973, 22 (23):3099-3108). Membranes were harvested by rapid filtration using the 96 well Brandel system (Table 1, Brandel) or a cell harvester (Table 1, Cell Harvester) using a Whatman GF/C filter or filter plates treated with 0.5% polyethylenimine (PEI), and washed 4 times with ice-cold 50 mM Tris/5 mM EDTA buffer. Filters were then dried, mixed with scintillant and radioactive counts were determined. Results for the compounds tested in these assays are presented in Table 1 as an average of results obtained (NT=not tested, ND=not determined). Compounds were tested in free base, hydrochloride salt, or trifluoroacetic acid form, with no significant differences in activities. Where activity is shown as greater than (>) a particular value, the value is the highest concentration tested.

TABLE 1 Cell Harvester Brandel Example # K_(i) (nM) K_(i) (nM) 1 0.5 1 2 3.83 3 7.26 4 4.9 5 8.9 6 35.1 7 13.7 8 10.6 9 0.4 1 10 0.5 0.5 11 12.9 12 19.2 13 26.2 14 114.39 15 148.9 54.3 16 48.19 17 375.49 18 527.35 19 NT 45.3 20 NT 3.5 21 NT 51.4 22 1.5 1.7 23 2.7 24 3.32 25 3.8 26 5.5 27 67.7 28 8.4 29 58.51 30 91.79 42.4 31 76.9 69.02 32 1.69 3.08 33 0.9 34 18.1 35 74.7 25.6 36 103.8 91.31 37 247.12 38 275.42 39 554.24 40 790.32 41 2.2 42 31.8 43 3.3 44 85.7 31.5 45 7.1 46 8.4 47 33.2 48 26.7 49 27.6 50 33.2 51 123.11 52 33.4 53 85.7 24.3 54 87.9 55 101.79 137.5 56 567.81 57 139.7 58 341.9 59 190.11 60 341.9 61 >10,000 62 >10,000 63 292.69 64 65.19 39 65 68.6 46.3 66 56.79 12.2 67 275.42 68 36.7 69 >10,000 70 73 240.27 71 377.14 72 376.27 73 0.7 2 74 1.2 75 1.5 76 1.8 77 3.3 78 6 79 11.6 80 23.5 81 24.7 82 45.5 83 195.79 84 33.3 85 18.2 86 33.7 87 33.7 88 42.7 89 69.29 26.2 90 105.61 68.9 91 182.18 92 615.32 93 701.62 94 868.36 95 15 15 96 1 1 97 5.9 5.9 98 4.8 4.8 99 23.9 23.9 100 31 31 101 >10,000 >10,000 102 45.93 103 167.9 104 1053 105 165 106 193.9 107 69.91 108 140.6 109 63.96 110 837.2 111 93.55 112 236.1 113 139.5 114 45.39 115 931.7 116 7.532 117 246.5 118 >10,000 119 22.87 120 302.7 121 1.569 122 64.71 123 2.038 124 155.4 125 2.096 126 19.84 127 1.659 128 843.9 129 141.4 130 849.2 131 820.4 132 1544 133 128.9 134 696.8 135 15.91 136 193.2 137 1378 138 23.82 139 7.958 140 135.3 141 2322 142 7094 143 266.8 144 2533 145 923 146 34.09 147 6.662 148 249.8 149 23.84 150 29.71 151 1459 152 2297 153 43.57 154 203.6 155 744.5 156 413.3 157 2144 158 3485 159 265.9 160 86.7 161 1301 162 7.137 163 277.7 164 36.2 165 731.9 166 >10,000 167 34.91 168 483.1 169 9.672 170 143.8 171 3.893 172 13.74 173 745.2 174 19.09 175 816.3 176 457.7 177 522.9 178 242.8 179 788.2 180 116.4 181 9.066 182 45.41 183 15.64 184 1.576 185 1732 186 690.6 187 71.55 188 449.7 188 5.729 190 1.678 191 3.575 192 2.419 193 15.97 194 5.07 195 7.75 196 224.5 197 17.34 198 54.99 199 2300 200 859.9 201 62.29 202 194.5 203 61.38 204 NT 205 no data 206 44.85 207 191.1 208 0.86 209 1458 210 295.8 211 1.684 212 274.6 213 156.7 214 415.9 215 69.65 216 1434 217 24.27 218 2.615 219 187.7 220 6.48 221 853.2 222 67.29 223 722.6 224 238.7 225 75.06 226 3.813 227 259.5 228 31.76 229 >10,000 230 275.9 231 8.412 232 716 233 215 234 7259 235 409.3 236 47.35 237 584.5 238 555.4 239 700.8 240 54.34 241 837.5 242 >10,000 243 167 244 3883 245 227.7 246 395.4 247 1.41 248 NT 249 257.4 250 658.9 251 79.38 252 190.4 253 4.33 254 27.54 255 1944 256 616.8 257 64.49 258 >10,000 259 5.148 260 >10,000 261 3563 262 22.07 263 3091 264 >10,000 265 1.71 266 14.47 267 1529 268 246.5 269 2099 270 3.526 271 189.3 272 2102 273 3166 274 10.57 275 8.548 276 1638 277 97.04 278 7.29 279 275.6 280 9.955 281 21.26 282 173.2 283 162.4 284 42.33 285 140.9 286 88.28 287 98.92 288 39.47 289 409.7 290 1479 291 238.9 292 7.01 293 60.94 294 103.3 295 162.9 296 64.23 297 1556 298 >10,000 299 146.2 300 1857 301 202.1 302 98.12 303 416.8 304 310.4 305 1059 306 7216 307 535.7 308 18.43 309 1597 310 620.8 311 226.3 312 546.8 313 >10,000 314 >10,000 315 1919 316 275.4 317 929.8 318 1237 319 478.3 320 4314 321 626.2 322 88.05 323 >10,000 324 898.7 325 797.8 326 2743 327 95.32 328 1677 329 >10,000 330 2586 331 96.73 332 1658 333 >10,000 334 2574 335 >10,000 336 >10,000 337 >10,000 338 >10,000 339 219.7 340 2033 341 >10,000 342 936.4 343 >10,000 344 >10,000 345 1316 346 >10,000 347 >10,000 348 >10,000 349 >10,000 350 1723 351 205.8 352 >10,000 353 105.6 354 2131 355 2900 356 1597 357 4370 358 >10,000 359 161.3 360 1171 361 1227 362 2212 363 4727 364 1743 365 508.1 366 >10,000 367 866.9 368 290.4 369 619.4 370 223.6 371 130.3 372 138.6 373 143.1 374 297.8 375 66.75 376 >10,000 377 698.9 378 6.164 379 296 380 54.29 381 5.51 382 138.5 383 596 384 2004 385 258.8 386 283.9 387 835.1 388 293.4 389 1745 390 >10,000 391 36.47 392 18.35 393 1807 394 633.6 395 1902 396 380.5 397 353.4 398 347.4 399 3941 400 2152 401 79.31 402 >10,000 403 >10,000 404 4303 405 >10,000 406 178.1 407 823.6 408 >10,000 409 >10,000 410 >10,000 411 NT 412 5.6 413 NT 414 NT 415 NT 416 NT

Cell-Based cAMP Assay

SK-N-MC cell lines were created that express a reporter gene construct and the human H₄ receptor full-coding region (NCBI accession No. AF312230). The reporter gene was β-galactosidase under the control of cyclic AMP-responsive elements. Cells were plated in 96-well plates the night before the assay. Histamine was used as the agonist for all assay. For the H4 receptor, the inhibition of forskolin-stimulated cAMP production was measured. For determination of antagonist activity, compounds were added 10 min prior to the addition of agonist, which was added directly to the cell medium. Forskolin (5 μM final concentration) was added 10 min after the addition of histamine. Cells were returned to the incubator for 6 h at 37° C. The medium was then aspirated, and the cells were washed with 200 mL of phosphate-buffered saline (PBS). Cells were lysed with 25 μL of 0.1× assay buffer (10 mM sodium phosphate, pH 8, 0.2 mM MgSO₄, and 0.01 mM MnCl₂) and incubated at rt for 10 min. Cells were then incubated for 10 min with 100 μL of 1× assay buffer containing 0.5% (v/v) Triton X-100 and 40 mM β-mercaptoethanol. Color was developed using 25 μL of 1 mg/mL substrate solution (chlorophenol red β-D-galactopyranoside; Roche Applied Science, Indianapolis, Ind.). Color was quantitated on a microplate reader by measuring the absorbance at 570 nm. The data from each concentration-response curve were fitted to a sigmoidal curve to obtain the maximum response, Hill coefficient, and EC₅₀ using Prism (GraphPad Software, San Diego, Calif.). Dose ratios were calculated from individual concentration-response curves of agonists at three to five antagonist concentrations. Apparent pA₂ values were calculated using a Schild plot (ND=not determined). Results for compounds tested in this assay are presented in Table 2.

Example # pA₂ 2 ND 3 8.7 4 8.86 12 8.5 20 7.7 22 9.24 32 11 33 ND 95 7.8 162 8.1 189 8 193 7.9 201 7.7 203 7.8 217 7.5 220 7.6 228 7.4 231 9 257 7.3 308 7.1 331 7.4 380 7.2 381 8.1 392 8.1

While the invention has been illustrated by reference to examples, it is understood that the invention is intended not to be limited to the foregoing detailed description.

Insulin Resistance in Diabetes Induced Obese Mouse Model.

The effect of administration of an H4R antagonist, 5-fluoro-4-methyl-2-{5-methyl-2-[4-(1-methyl-piperidin-4-yl)-butoxy]-pyridin-4-yl}-1H-benzoimidazole (U.S. Pat. No. 7,432,378, Example 185), was tested in the treatment of insulin resistance in the diabetes induced obese (DIO) mouse model. 5-Fluoro-4-methyl-2-{5-methyl-2-[4-(1-methyl-piperidin-4-yl)-butoxy]-pyridin-4-yl}-1H-benzoimidazole (20 mg/kg PO) significantly reduced fed and fasted glucose levels and improved insulin sensitivity as determined by an insulin tolerance test. 5-Fluoro-4-methyl-2-{5-methyl-2-[4-(1-methyl-piperidin-4-yl)-butoxy]-pyridin-4-yl}-1H-benzoimidazole significantly reduced fat content in liver and reduced MCP-1 and TNF-α expression. Our data support the claim that H4R antagonists have beneficial properties towards the treatment of type 2 diabetes and related metabolic diseases. 

What is claimed is:
 1. A chemical entity selected from the compounds of Formula (I)

wherein Z is CH or N; Y is CH; Z and Y are defined independently of each other; R¹ is: a) —(CH₂)₂OCH₃, —(CH₂)₂SCH₃, or C₁₋₈alkyl, each independently unsubstituted or substituted with —OH or —CF₃; b) —(CH₂)₀₋₂—Ar¹, —CHR²—Ar¹, or —(CH₂)₀₋₂—Ar², each of said Ar¹ and Ar² independently unsubstituted or substituted with halo, —CH₃, or —OCH₃, Ar¹ is a 6-membered aromatic carbocyclic ring, Ar² is a 5 to 6-membered heteroaromatic ring containing N, S or O; or c) cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CH₂)-(bridged polycyclic cycloalkyl)₀₋₁, —(CHR²)-(monocyclic cycloalkyl), —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged monocyclic cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, or —(CH₂)₀₋₁-tetrahydropyranyl, each of said cycloalkyl independently unsubstituted or substituted with one, two, or three C₁₋₄alkyl substituents; R² is —C₁₋₄alkyl;

where R^(a), R^(b), and R^(c) are each independently H or C₁₋₃alkyl; provided that: when R¹ is isopropyl, then R^(c) is methyl; when R¹ is 4-methylphenyl, then R^(c) is methyl; when Z is N, Y is CH, and R¹ is benzyl unsubstituted or substituted with halo, then R^(c) is methyl; and pharmaceutically acceptable salts of compounds of Formula (I). 2-3. (canceled)
 4. A chemical entity of claim 1, wherein R¹ is selected from the group consisting of: a) C₁₋₈ alkyl unsubstituted or substituted with —OH or —CF₃; b) phenyl, pyridyl, benzyl, pyridin-2-ylmethyl, phenylethyl, 1-phenyl-ethyl, each independently unsubstituted or substituted with halo, —CH₃, —OCH₃; and c) cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CHR²)-(monocyclic cycloalkyl), —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged polycyclic cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, and —(CH₂)₀₋₁-tetrahydropyranyl, each independently unsubstituted or substituted with one, two, or three C₁₋₄alkyl substituents.
 5. A chemical entity of claim 1, wherein R¹ selected from the group consisting of: a) 2,2-dimethylpropanol, 2,2-dimethylpropan-1-ol, 2,2-dimethylpropyl, 2-methyl-1-propan-2-ol, 2-methylpropan-2-ol, 3-propanol, (1-methylethyl), 2-methoxyethyl, 2-methylpropyl, 4,4,4-trifluorobutyl, propyl, butyl, tert-butyl, propan-1-ol, 2-(methylsulfanyl)ethyl; b) 2-phenylethyl, furan-3-ylmethyl, pyridin-2-ylmethyl, (1R)-1-phenylethyl, benzyl, phenyl, 4-fluorobenzyl, 4-methoxybenzyl, 4-methylbenzyl; and c) bicyclo[2.2.1]hept-2-ylmethyl, tetrahydro-2H-pyran-4-yl, tetrahydrofuran-2-ylmethyl, (1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl, (1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (1S,2S,4R)-bicyclo[2.2.1]hept-2-yl, (1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl, (2R)-tetrahydrofuran-2-ylmethyl, (2S)-bicyclo[2.2.1]hept-2-yl], [(2S)-tetrahydrofuran-2-ylmethyl, (3R)-tetrahydrofuran-3-yl, (6,6-dimethylbicyclo[3.1.1]hept-2-yl)methyl, bicyclo[2.2.1]hept-2-yl, cyclobutyl, cyclohexyl, cyclopentyl, cyclopropyl, cyclohexylmethyl, cyclopentylmethyl, cyclopropylmethyl, adamantan-1-yl, and 2-adamantyl.
 6. A chemical entity of claim 1, wherein R¹ is selected from the group consisting of:


7. A chemical entity of claim 1, wherein

is selected from the group consisting of:


8. A chemical entity of claim 1, wherein

is


9. A chemical entity of claim 1, wherein

is


10. A chemical entity of claim 1, wherein

is


11. A chemical entity of claim 1, wherein

is


12. A chemical entity of claim 1, wherein

is


13. A chemical entity of claim 1, wherein R^(a) is H.
 14. A chemical entity of claim 1, wherein R^(b) is H or methyl.
 15. A chemical entity of claim 1, wherein R^(c) is H or methyl.
 16. A chemical entity of claim 1, wherein R² is methyl.
 17. A chemical entity of claim 1, wherein Z is CH.
 18. A chemical entity of claim 1, wherein Z is N. 19-32. (canceled)
 33. A chemical entity selected from the group consisting of: Bicyclo[2.2.1]hept-2-yl-[4-((3R)-3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine dihydrochloride; N-Cyclopentyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-propylpyridin-2-amine dihydrochloride; N-(Cyclopropylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine ditrifluoroacetate; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(3R)-tetrahydrofuran-3-yl]pyridin-2-amine dihydrochloride; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[tetrahydrofuran-2-ylmethyl]pyridin-2-amine dihydrochloride; N-(4-Fluorobenzyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine dihydrochloride; N-Cyclopropyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine dihydrochloride; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; N-Benzyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(1-methylethyl)pyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(1-methylethyl)pyridin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine; 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine; N-Cyclopentyl-4-piperazin-1-ylpyridin-2-amine; 4-Piperazin-1-yl-N-propylpyridin-2-amine dihydrochloride; N-Benzyl-4-piperazin-1-ylpyridin-2-amine; N-(2-Methylpropyl)-4-piperazin-1-ylpyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-(2-methylpropyl)pyridin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-phenylpyridin-2-amine; 4-[3-(Methylamino)azetidin-1-yl]-N-(2-methylpropyl)pyridin-2-amine; N-(Cyclopropylmethyl)-4-piperazin-1-ylpyridin-2-amine; N-Butyl-4-piperazin-1-ylpyridin-2-amine; N-(2-Methoxyethyl)-4-piperazin-1-ylpyridin-2-amine; N-Phenyl-4-piperazin-1-ylpyridin-2-amine; 4-Piperazin-1-yl-N-(tetrahydrofuran-2-ylmethyl)pyridin-2-amine; N-(4-Fluorobenzyl)-4-piperazin-1-ylpyridin-2-amine; N-(2,2-Dimethylpropyl)-4-[(3R)-3-(methylamino)pyrrolidin-2-yl]pyridin-2-amine; N-(2-Methoxyethyl)-4-[(3R)-3-(methylamino)pyrrolidin-2-yl]pyridin-2-amine; 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyridin-2-amine; Adamantan-2-yl-[4-(4-methyl-piperazin-1-yl)-pyridin-2-yl]-amine; Adamantan-2-yl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine; N-[(1R)-1-Cyclohexylethyl]-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; Adamantan-1-yl-[4-(3S)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine; N-(Cyclohexylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-(Cyclohexylmethyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine; N-[(1R)-1-Cyclohexylethyl]-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-[(1R)-1-Cyclohexylethyl]-4-(4-methylpiperazin-1-yl)pyridin-2-amine; Adamantan-2-yl-[4-(3S)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine; 3-{[4-(4-Methylpiperazin-1-yl)pyridin-2-yl]amino}propan-1-ol; N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; Adamantan-1-yl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine; Adamantan-1-yl-[4-(4-methyl-piperazin-1-yl)-pyridin-2-yl]-amine; Adamantan-1-ylmethyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine; N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-(4-methylpiperazin-1-yl)pyridin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine; N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-(Cyclohexylmethyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2amine; N-(Cyclopentylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-(Cyclopentylmethyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-Cyclopentyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyridin-2-amine; 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; N-Bicyclo[2.2.1]hept-2-yl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; N-tert-Butyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 3-({4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]pyridin-2-yl}amino)propan-1-ol; N-Cyclopropyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-(Cyclopentylmethyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine; N-Benzyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-(2-Methoxyethyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; N-(2-Methoxyethyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine; 2-Methyl-1-({4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-yl}amino)propan-2-ol; 2-Methyl-1-{[4-(4-methylpiperazin-1-yl)pyridin-2-yl]amino}propan-2-ol; 2-Methyl-1-({4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-yl}amino)propan-2-ol; N-Butyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-(pyridin-2-ylmethyl)pyridin-2-amine; 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-phenylethyl)pyridin-2-amine; N-(4-Fluorobenzyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyridin-2-amine; N-Cyclopentyl-4-(4-methylpiperazin-1-yl)pyridin-2-amine; N-(4-Fluorobenzyl)-4-(4-methylpiperazin-1-yl)pyridin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-(2-phenylethyl)pyridin-2-amine; Adamantan-1-ylmethyl-[4-(3S)-(3-methylamino-pyrrolidin-1-yl)-pyridin-2-yl]-amine; 4-(4-Methylpiperazin-1-yl)-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyridin-2-amine; N-(Bicyclo[2.2.1]hept-2-ylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-butylpyridin-2-amine; Adamantan-1-ylmethyl-[4-(4-methyl-piperazin-1-yl)-pyridin-2-yl]-amine; N-(Cyclohexylmethyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine; 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(2-methylpropyl)pyridin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyridin-2-amine; N-Cyclopentyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine; 4-Piperazin-1-yl-N-(pyridin-2-ylmethyl)pyridin-2-amine; N-(Cyclopentylmethyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine; N-Cyclopentyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(4-fluorobenzyl)pyridin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyridin-2-amine; N-Bicyclo[2.2.1]hept-2-yl-4-(1,4-diazepan-1-yl)pyridin-2-amine; Adamantan-2-yl-[4-(3aR,6aR)-(hexahydro-pyrrolo[3,4-b]pyrrol-5-yl)-pyridin-2-yl]-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-benzylpyridin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyridin-2-amine; 4-Piperazin-1-yl-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-bicyclo[2.2.1]hept-2-ylpyridin-2-amine; N-[(1R)-1-Cyclohexylethyl]-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; 1-({4-[(3S)-3-Aminopyrrolidin-1-yl]pyridin-2-yl}amino)-2-methylpropan-2-ol; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclohexylpyridin-2-amine; N-(Cyclopentylmethyl)-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-phenylethyl)pyridin-2-amine; 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyridin-2-amine; 1-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyridin-2-yl}amino)-2-methylpropan-2-ol; N-tert-Butyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine; N-Cyclopropyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine; 2-Methyl-1-({4-[3-(methylamino)azetidin-1-yl]pyridin-2-yl}amino)propan-2-ol; 3-({4-[3-(Methylamino)azetidin-1-yl]pyridin-2-yl}amino)propan-1-ol; 4-[3-(Methylamino)azetidin-1-yl]-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; N-Benzyl-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine; N-(2-Methoxyethyl)-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine; 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-[(1S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyridin-2-amine; N-tert-Butyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyridin-2-amine; 2-Methyl-1-[(4-piperazin-1-ylpyridin-2-yl)amino]propan-2-ol; N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyridin-2-amine; N-(2,2-Dimethylpropyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyridin-2-amine; 4-[3-(Methylamino)azetidin-1-yl]-N-(2-phenylethyl)pyridin-2-amine; N-(4-Fluorobenzyl)-4-[3-(methylamino)azetidin-1-yl]pyridin-2-amine; Adamantan-1-yl-[4-(3aR,6aR)-(hexahydro-pyrrolo[3.4-b]pyrrol-5-yl)-pyridin-2-yl]-amine; 4-[3-(Methylamino)azetidin-1-yl]-N-(pyridin-2-ylmethyl)pyridin-2-amine; N-(Cyclopentylmethyl)-4-piperazin-1-ylpyridin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclopropylmethyl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2,2-dimethylpropyl)pyrimidin-2-amine; 1-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2-methylpropan-2-ol; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclobutylpyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(3R)-tetrahydrofuran-3-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(tetrahydro-2H-pyran-4-yl)pyrimidin-2-amine; Isobutyl-[4-(4-methyl-piperazin-1-yl)-pyrimidin-2-yl]-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[bicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine; N-[Bicyclo[2.2.1]hept-2-yl]-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; N-(Cyclopropylmethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-butylpyrimidin-2-amine; N-Butyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; N-Cyclopentyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; N-(2,2-Dimethylpropyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-(tetrahydrofuran-2-ylmethyl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(tetrahydrofuran-2-ylmethyl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(1-methylethyl)pyrimidin-2-amine; N-(1-Methylethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; N-Cyclobutyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclopropylpyrimidin-2-amine N-Cyclopropyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-fluorobenzyl)pyrimidin-2-amine; N-(4-Fluorobenzyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyrimidin-2-amine; N-(2-Methoxyethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-(pyridin-2-ylmethyl)pyrimidin-2-amine; Cyclopentyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine; (2,2-Dimethyl-propyl)-(4-piperazin-1-yl-pyrimidin-2-yl)-amine. Isobutyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine; Cyclopropylmethyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine; Isopropyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine; Butyl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine; (R)-(4-Piperazin-1-yl-pyrimidin-2-yl)-(tetrahydro-furan-2-ylmethyl)-amine; Bicyclo[2.2.1]hept-2-yl-(4-piperazin-1-yl-pyrimidin-2-yl)-amine; (4-Piperazin-1-yl-pyrimidin-2-yl)-(2,6,6-trimethyl-bicyclo[3.1.1]hept-3-yl)-amine. N-(2-Methoxyethyl)-4-piperazin-1-ylpyrimidin-2-amine; Butyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; Bicyclo[2.2.1]hept-2-yl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; Cyclopentyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; (2,2-Dimethyl-propyl)-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; Cyclopropylmethyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; Isopropyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; (4-Fluoro-benzyl)-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; Cyclopropyl-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; [4-(3R)-(3-Methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-(tetrahydro-furan-2-ylmethyl)-amine; (2-Methoxy-ethyl)-[4-(3R)-(3-methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-amine; [4-(3R)-(3-Methylamino-pyrrolidin-1-yl)-pyrimidin-2-yl]-pyridin-2-ylmethyl-amine; [4-(3-Amino-azetidin-1-yl)-pyrimidin-2-yl]-butyl-amine; 4-(3-Aminoazetidin-1-yl)-N-cyclopentylpyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-(cyclopropylmethyl)pyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-bicyclo[2.2.1]hept-2-ylpyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-(2,2-dimethylpropyl)pyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-(2-methylpropyl)pyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-(1-methylethyl)pyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-cyclopropylpyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-(4-fluorobenzyl)pyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-[(3R)-tetrahydrofuran-3-yl]pyrimidin-2-amine; 4-(3-Aminoazetidin-1-yl)-N-[(2R)-tetrahydrofuran-2-ylmethyl]pyrimidin-2-amine; N-(Cyclohexylmethyl)-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1 R)-1-cyclohexylethyl]pyrimidin-2-amine; N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine; N-[(6,6-Dimethylbicyclo[3.1.1]hept-2-yl)methyl]-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(6,6-dimethylbicyclo[3.1.1]hept-2-yl)methyl]pyrimidin-2-amine; N-(Cyclohexylmethyl)-4-[(3aR,6aR)-hexahydropyrrolo[3.4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine; 4-[3-(Methylamino)azetidin-1-yl]-N-(tetrahydro-2H-pyran-4-yl)pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(cyclopropylmethyl)pyrimidin-2-amine; 1-({4-[(3S)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2-methylpropan-2-ol; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2,2-dimethylpropyl)pyrimidin-2-amine; N-Cyclopropyl-4-piperazin-1-ylpyrimidin-2-amine; N-[(1R)-1-Cyclohexylethyl]-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine; 2-Methyl-1-({4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-2-ol; N-[(1R)-1-Cyclohexylethyl]-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(2-phenylethyl)pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-2-amine; N-(Cyclopentylmethyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 2-Methyl-1-{[4-(4-methylpiperazin-1-yl)pyrimidin-2-yl]amino}propan-2-ol; N-(Cyclopentylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; 2-Methyl-1-({4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-yl}amino)propan-2-ol; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyrimidin-2-amine; N-[2-(Methylsulfanyl)ethyl]-4-piperazin-1-ylpyrimidin-2-amine; 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine; 4-[3-(Methylamino)azetidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methoxyethyl)pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-cyclohexylpyrimidin-2-amine; 3-({4-[(3S)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2,2-dimethylpropan-1-ol; N-Benzyl-4-piperazin-1-ylpyrimidin-2-amine; N-(2-Phenylethyl)-4-piperazin-1-ylpyrimidin-2-amine; N-Bicyclo[2.2.1]hept-2-yl-4-piperazin-1-ylpyrimidin-2-amine; 4-Piperazin-1-yl-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyrimidin-2-amine; 3-({4-[3-(Methylamino)azetidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol; 2,2-Dimethyl-3-({4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol; 3-[(4-Piperazin-1-ylpyrimidin-2-yl)amino]propan-1-ol; 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(2-methylpropyl)pyrimidin-2-amine; N-Cyclopentyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine; 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-(2-methoxyethyl)pyrimidin-2-amine; 4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-N-[(1R)-1-phenylethyl]pyrimidin-2-amine; N-(4-Fluorobenzyl)-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine; N-Cyclopropyl-4-[(3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-amine; N-(4-Methoxybenzyl)-4-piperazin-1-ylpyrimidin-2-amine; N-Cyclopropyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-bicyclo[2.2.1]hept-2-ylpyrimidin-2-amine; N-Bicyclo[2.2.1]hept-2-yl-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine; 3-({4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-yl}amino)-2,2-dimethylpropan-1-ol; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(cyclopentylmethyl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4,4,4-trifluorobutyl)pyrimidin-2-amine; 3-{[4-(3-Aminoazetidin-1-yl)pyrimidin-2-yl]amino}-2,2-dimethylpropan-1-ol; 3-({4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol; 3-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)-2,2-dimethylpropan-1-ol; 3-({4-[(3R)-3-Aminopyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol; 3-{[4-(3-Aminoazetidin-1-yl)pyrimidin-2-yl]amino}propan-1-ol; N-(4-Methylbenzyl)-4-piperazin-1-ylpyrimidin-2-amine; 4-Piperazin-1-yl-N-(pyridin-2-ylmethyl)pyrimidin-2-amine; 2,2-Dimethyl-3-({4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol; 3-({4-[(3aR,6aR)-Hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]pyrimidin-2-yl}amino)propan-1-ol; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-cyclopentylpyrimidin-2-amine; 3-{[4-(4-Methylpiperazin-1-yl)pyrimidin-2-yl]amino}propan-1-ol; N-Bicyclo[2.2.1]hept-2-yl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; N-(4-Methylbenzyl)-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-[2-(methylsulfanyl)ethyl]pyrimidin-2-amine; N-Benzyl-4-(4-methylpiperazin-1-yl)pyrimidin-2-amine; 2,2-Dimethyl-3-[(4-piperazin-1-ylpyrimidin-2-yl)amino]propan-1-ol; 3-({4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol; 4-(4-Methylpiperazin-1-yl)-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyrimidin-2-amine; 2,2-Dimethyl-3-({4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-yl}amino)propan-1-ol; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(4-methylbenzyl)pyrimidin-2-amine; 4-[3-(Methylamino)azetidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine; N-Cyclopentyl-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine; 4-(4-Methylpiperazin-1-yl)-N-(2-phenylethyl)pyrimidin-2-amine; N-Benzyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1R)-1-phenylethyl]pyrimidin-2-amine; N-(4-Methoxybenzyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; 2-Methyl-1-[(4-piperazin-1-ylpyrimidin-2-yl)amino]propan-2-ol; N-(4-Fluorobenzyl)-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-benzylpyrimidin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R)-1-phenylethyl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-cyclohexylpyrimidin-2-amine; N-(2-Methoxyethyl)-4-[3-(methylamino)azetidin-1-yl]pyrimidin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-phenylethyl)pyrimidin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1S,2S,3S,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-methoxybenzyl)pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(4-methylbenzyl)pyrimidin-2-amine; N-(Cyclopentylmethyl)-4-piperazin-1-ylpyrimidin-2-amine; 4-[3-(Methylamino)azetidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(3S,5S,7S)-tricyclo[3.3.1.1.3.7]dec-1-ylmethyl]pyrimidin-2-amine; 4-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-[(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]pyrimidin-2-amine; N-(Cyclohexylmethyl)-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; N-Cyclohexyl-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; N-{[(1S,2S,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-yl]methyl}-4-[(3R)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; 4-(1,4-Diazepan-1-yl)-N-(2,2-dimethylpropyl)pyrimidin-2-amine; N-Bicyclo[2.2.1]hept-2-yl-4-(1,4-diazepan-1-yl)pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-butylpyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-(cyclohexylmethyl)pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine; 4-[(3S)-3-Aminopyrrolidin-1-yl]-N-(4-fluorobenzyl)pyrimidin-2-amine; 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(pyridin-2-ylmethyl)pyrimidin-2-amine; N-Cyclopentyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; 4-[(3S)-3-(Methylamino)pyrrolidin-1-yl]-N-(2-methylpropyl)pyrimidin-2-amine; N-(2,2-Dimethylpropyl)-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; N-Benzyl-4-[(3S)-3-(methylamino)pyrrolidin-1-yl]pyrimidin-2-amine; 4-[(3R)-3-Aminopyrrolidin-1-yl]-N-[(1r,5R,7S)-tricyclo[3.3.1.1.3.7]dec-2-yl]pyrimidin-2-amine, and pharmaceutically acceptable salts thereof.
 34. (canceled)
 35. A pharmaceutical composition comprising an effective amount of at least one chemical entity selected from the compounds of Formula (I)

wherein Z is CH or N; Y is CH; Z and Y are defined independently of each other; R¹ is: a) —(CH₂)₂OCH₃, —(CH₂)₂SCH₃, or C₁₋₈alkyl, each independently unsubstituted or substituted with —OH or —CF₃; b) —(CH₂)₀₋₂—Ar¹, —CHR²—Ar¹, or —(CH₂)₀₋₂—Ar², each of said Ar¹ and Ar² independently unsubstituted or substituted with halo, —CH₃, or —OCH₃, Ar¹ is a 6-membered aromatic carbocyclic ring, Ar² is a 5 to 6-membered heteroaromatic ring containing N, S or O; or c) cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CH₂)-(bridged polycyclic cycloalkyl)₀₋₁, —(CHR²)-(monocyclic cycloalkyl), —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged monocyclic cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, or —(CH₂)₀₋₁-tetrahydropyranyl, each of said cycloalkyl independently unsubstituted or substituted with one, two, or three C₁₋₄alkyl substituents; R² is -C₁₋₄alkyl;

where R^(a), R^(b), and R^(c) are each independently H or C₁₋₃alkyl; provided that: when R¹ is isopropyl, then R^(c) is methyl; when R¹ is 4-methylphenyl, then R^(c) is methyl; when Z is N, Y is CH, and R¹ is benzyl unsubstituted or substituted with halo, then R^(c) is methyl; and pharmaceutically acceptable salts of compounds of Formula (I). 36-37. (canceled)
 38. A pharmaceutical composition comprising and effective amount of at least one chemical entity of claim
 33. 39. (canceled)
 40. A method of treating a subject suffering from or diagnosed with a disease, disorder, or medical condition mediated by histamine H₄ receptor activity, comprising administering to a subject in need of such treatment an effective amount of at least one chemical entity selected from compounds of Formula (I)

wherein Z is CH or N; Y is CH; Z and Y are defined independently of each other; R¹ is: a) —(CH₂)₂OCH₃, —(CH₂)₂SCH₃, or C₁₋₈alkyl, each independently unsubstituted or substituted with —OH or —CF₃; b) —(CH₂)₀₋₂—Ar¹, —CHR²—Ar¹, or —(CH₂)₀₋₂—Ar², each of said Ar¹ and Ar² independently unsubstituted or substituted with halo, —CH₃, or —OCH₃, Ar¹ is a 6-membered aromatic carbocyclic ring, Ar² is a 5 to 6-membered heteroaromatic ring containing N, S or O; or c) cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CH₂)-(bridged polycyclic cycloalkyl)₀₋₁, —(CHR²)-(monocyclic cycloalkyl), —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged monocyclic cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, or —(CH₂)₀₋₁-tetrahydropyranyl, each of said cycloalkyl independently unsubstituted or substituted with one, two, or three C₁₋₄alkyl substituents; R² is —C₁₋₄alkyl;

where R^(a), R^(b), and R^(c) are each independently H or C₁₋₃alkyl; provided that: when R¹ is isopropyl, then R^(c) is methyl; when R¹ is 4-methylphenyl, then R^(c) is methyl; when Z is N, Y is CH, and R¹ is benzyl unsubstituted or substituted with halo, then R^(c) is methyl; and pharmaceutically acceptable salts of compounds of Formula (I). 41-42. (canceled)
 43. A method of treating a subject suffering from or diagnosed with a disease, disorder, or medical condition mediated by histamine H₄ receptor activity, comprising administering to a subject in need of such treatment an effective amount of at least one chemical entity of claim
 33. 44. (canceled)
 45. A method as in claim 40, wherein the disease, disorder or medical condition is inflammation.
 46. A method as in claim 40, wherein the disease, disorder, or medical condition is selected from the group consisting of: inflammatory disorders, allergic disorders, dermatological disorders, autoimmune disease, lymphatic disorders, and immunodeficiency disorders.
 47. A method as in claim 40, wherein the disease, disorder, or medical condition is selected from: allergy, asthma, dry eye, chronic obstructed pulmonary disease (COPD), atherosclerosis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases, colitis, Crohn's disease, ulcerative colitis, psoriasis, pruritus, itchy skin, atopic dermatitis, urticaria, hives, ocular inflammation, conjunctivitis, dry eye, nasal polyps, allergic rhinitis, nasal itch, scleroderma, autoimmune thyroid diseases, post-operative adhesion, immune-mediated diabetes mellitus (type 1), type 2 diabetes, chronic renal failure, hepatic cholestasis, lupus, Myasthenia gravis, autoimmune neuropathies, Guillain-Barré, autoimmune uveitis, autoimmune hemolytic anemia, pernicious anemia, autoimmune thrombocytopenia, temporal arteritis, anti-phospholipid syndrome, vasculitides, Wegener's granulomatosis, Behcet's disease, dermatitis herpetiformis, pemphigus vulgaris, vitiligio, primary biliary cirrhosis, autoimmune hepatitis, autoimmune oophoritis, autoimmune orchitis, autoimmune disease of the adrenal gland, polymyositis, dermatomyositis, spondyloarthropathies, ankylosing spondylitis, Sjogren's syndrome, major depression disorder, bipolar disorder, treatment-resistant major depression disorder, treatment-resistant bipolar disorder, generalized anxiety disorder, social phobia, post traumatic stress disorder, and pain.
 48. A method as in claim 40, wherein the disease, disorder, or medical condition is selected from the group consisting of: allergy, asthma, rheumatoid arthritis, autoimmune diseases, and pruritus.
 49. A method for modulating histamine H₄ receptor activity, comprising exposing histamine H₄ receptor to an effective amount of at least one chemical entity selected from compounds of Formula (I)

wherein Z is CH or N; Y is CH; Z and Y are defined independently of each other; R¹ is: a) —(CH₂)₂OCH₃, —(CH₂)₂SCH₃, or C₁₋₈alkyl, each independently unsubstituted or substituted with —OH or —CF₃; b) —(CH₂)₀₋₂—Ar¹, —CHR²—Ar¹, or —(CH₂)₀₋₂—Ar², each of said Ar¹ and Ar² independently unsubstituted or substituted with halo, —CH₃, or —OCH₃, Ar¹ is a 6-membered aromatic carbocyclic ring, Ar² is a 5 to 6-membered heteroaromatic ring containing N, S or O; or c) cycloalkyl, —(CH₂)-(monocyclic cycloalkyl), —(CH₂)-(bridged polycyclic cycloalkyl)₀₋₁, —(CHR²)-(monocyclic cycloalkyl), —(CH₂)-(fused cycloalkyl), —(CH₂)-(bridged monocyclic cycloalkyl), —(CH₂)₀₋₁-tetrahydrofuranyl, or —(CH₂)₀₋₁-tetrahydropyranyl, each of said cycloalkyl independently unsubstituted or substituted with one, two, or three C₁₋₄alkyl substituents; R² is —C₁₋₄alkyl;

where R^(a), R^(b), and R^(c) are each independently H or C₁₋₃alkyl; provided that: when R¹ is isopropyl, then R^(c) is methyl; when R¹ is 4-methylphenyl, then R^(c) is methyl; when Z is N, Y is CH, and R¹ is benzyl unsubstituted or substituted with halo, then R^(c) is methyl; and pharmaceutically acceptable salts of compounds of Formula (I). 50-51. (canceled)
 52. A method for modulating histamine H₄ receptor activity, comprising exposing histamine H₄ receptor to an effective amount of at least one chemical entity of claim
 33. 53. (canceled)
 54. A method as in claim 49, wherein said histamine H₄ receptor is in a human subject.
 55. A method as in claim 54, wherein said human subject is suffering from or is diagnosed with a disease, disorder, or medical condition mediated by histamine H₄ receptor activity.
 56. A method as in claim 55, wherein said disease, disorder, or medical condition is allergy, rheumatoid arthritis, asthma, autoimmune diseases, or pruritus.
 57. A method as in claim 40, wherein said administration comprises a topical application.
 58. A method as in claim 57, wherein said disorder or medical condition is inflammation.
 59. A method as in claim 57, wherein said disorder or medical condition is at least one of pruritus, urticaria and atopic dermatitis. 